Freezing Dates
Using the NWS COOP data archive, significant dates relating to fall are
extracted and presented on this page. The specific dates are the first
occurance of that temperature and may have occured again in subsequent
years.
The "Record Lows" columns show the first fall occurance of a low
temperature. The "Average Lows" column shows when certain climatological
thresholds are surpassed in the fall.
| COOP Site: | Record Lows: | Average Lows: | |||||
|---|---|---|---|---|---|---|---|
| Temp <= 32°F | Temp <= 28°F | Below 40°F | Below 32°F | Below 28°F | Temp: | Date: | Temp: | Date: |
| Spencer Area | -1 | -08-16 | -1 | -08-16 | 10-09 | 10-27 | 11-08 |
| Spencer Airport | -1 | -08-16 | -1 | -08-16 | 10-07 | 10-26 | 11-10 |
| SIBLEY-5-NNE | 30 | -08-20 | 23 | -09-11 | 10-07 | 10-26 | 11-03 |
| JEFFERSON | 32 | -08-29 | 28 | -09-18 | 10-17 | 11-02 | 11-11 |
| Elkader 6SSW (Osborn) | 32 | -08-29 | 0 | -09-02 | 10-09 | 10-28 | 11-10 |
| BELLEVUE-L-AND-D-12 | 32 | -08-30 | 28 | -09-23 | 10-17 | 11-06 | 11-21 |
| IOWA-FALLS | 31 | -08-30 | 28 | -09-18 | 10-13 | 11-01 | 11-10 |
| Mason City Area | 30 | -08-30 | 28 | -09-14 | 10-10 | 10-27 | 11-09 |
| Mason City | 30 | -08-30 | 28 | -09-14 | 10-10 | 10-28 | 11-09 |
| ALLISON | 32 | -08-30 | 28 | -09-25 | 10-17 | 11-02 | 11-11 |
| DECORAH-2-N | 32 | -08-30 | 28 | -09-02 | 10-10 | 11-01 | 11-11 |
| CASCADE | 32 | -08-31 | 28 | -09-22 | 10-10 | 11-03 | 11-11 |
| FOREST-CITY | 31 | -09-01 | 27 | -09-18 | 10-13 | 10-28 | 11-09 |
| FAYETTE | 32 | -09-01 | 27 | -09-12 | 10-10 | 10-28 | 11-10 |
| NEW-HAMPTON | 28 | -09-01 | 28 | -09-01 | 10-13 | 11-01 | 11-10 |
| POCAHONTAS | 31 | -09-02 | 27 | -09-18 | 10-12 | 10-28 | 11-10 |
| ALGONA | 29 | -09-02 | 27 | -09-18 | 10-17 | 11-01 | 11-10 |
| Postville | 32 | -09-02 | 20 | -09-21 | 10-17 | 11-02 | 11-11 |
| ATLANTIC-1-NE | 30 | -09-02 | 28 | -09-12 | 10-16 | 11-01 | 11-10 |
| SAC-CITY | 32 | -09-03 | 28 | -09-20 | 10-16 | 11-01 | 11-11 |
| Milford | 32 | -09-03 | 28 | -09-18 | 10-13 | 10-31 | 11-08 |
| SANBORN | 32 | -09-03 | 25 | -09-18 | 10-13 | 10-27 | 11-07 |
| Spencer | 31 | -09-03 | 28 | -09-15 | 10-09 | 10-27 | 11-08 |
| FORT-DODGE | 32 | -09-03 | 27 | -09-13 | 10-16 | 11-01 | 11-11 |
| ROCK-RAPIDS | 31 | -09-03 | 26 | -09-10 | 10-07 | 10-24 | 11-05 |
| Emmetsburg | 0 | -09-03 | 0 | -09-03 | 10-13 | 11-01 | 11-10 |
| CARROLL-2-SSW | 28 | -09-03 | 28 | -09-03 | 10-16 | 11-01 | 11-10 |
| SIOUX CENTER 2 SE | 31 | -09-03 | 24 | -09-19 | 10-16 | 10-31 | 11-10 |
| SIOUX-RAPIDS | 31 | -09-03 | 28 | -09-19 | 10-09 | 10-27 | 11-09 |
| Ida Grove Area | 32 | -09-03 | 27 | -09-20 | 10-16 | 10-31 | 11-10 |
| OAKLAND-2-E | 32 | -09-03 | 28 | -09-22 | 10-17 | 11-03 | 11-11 |
| SWEA CITY 4 W | 32 | -09-03 | 26 | -09-22 | 10-09 | 10-29 | 11-10 |
| CHEROKEE | 31 | -09-03 | 27 | -09-11 | 10-07 | 10-27 | 11-07 |
| STANLEY | 32 | -09-07 | 26 | -09-23 | 10-11 | 10-27 | 11-01 |
| Estherville 4E | 32 | -09-09 | 27 | -09-18 | 10-07 | 10-27 | 11-06 |
| GRINNELL-3-SW | 31 | -09-10 | 27 | -09-20 | 10-17 | 11-02 | 11-11 |
| Oelwein Area | 28 | -09-11 | 28 | -09-11 | 10-10 | 11-02 | 11-11 |
| Waterloo Area | 32 | -09-11 | 28 | -09-18 | 10-13 | 11-02 | 11-11 |
| KEOSAUQUA | 31 | -09-11 | 28 | -09-18 | 10-24 | 11-09 | 11-22 |
| FAIRFIELD | 32 | -09-11 | 28 | -09-21 | 10-24 | 11-08 | 11-22 |
| WATERLOO | 32 | -09-11 | 28 | -09-18 | 10-13 | 11-02 | 11-11 |
| BELLE-PLAINE | 31 | -09-11 | 28 | -09-18 | 10-17 | 11-02 | 11-12 |
| RED-OAK | 32 | -09-11 | 28 | -09-22 | 10-19 | 11-03 | 11-21 |
| MAPLETON NO. 2 | 31 | -09-11 | 27 | -09-19 | 10-15 | 11-02 | 11-10 |
| WILLIAMSBURG | 32 | -09-11 | 28 | -09-20 | 10-18 | 11-03 | 11-12 |
| WEBSTER-CITY | 30 | -09-11 | 25 | -09-18 | 10-13 | 10-28 | 11-10 |
| Le Mars | 31 | -09-11 | 28 | -09-12 | 10-12 | 10-29 | 11-08 |
| TOLEDO | 31 | -09-11 | 27 | -09-20 | 10-17 | 11-02 | 11-11 |
| MAQUOKETA-2-W | 31 | -09-11 | 28 | -09-23 | 10-17 | 11-02 | 11-12 |
| HAMPTON-2-NW | 32 | -09-11 | 28 | -09-12 | 10-12 | 11-01 | 11-10 |
| ROCKWELL-CITY | 32 | -09-12 | 28 | -09-18 | 10-17 | 11-01 | 11-10 |
| DENISON | 29 | -09-12 | 21 | -09-21 | 10-18 | 11-02 | 11-11 |
| GRUNDY-CENTER | 32 | -09-12 | 28 | -09-18 | 10-13 | 11-02 | 11-11 |
| Boone | 32 | -09-12 | 27 | -09-18 | 10-17 | 11-02 | 11-11 |
| Iowa Drought Region 2 - Northcentral | 32 | -09-12 | 27 | -09-22 | 10-17 | 11-02 | 11-11 |
| GUTHRIE-CENTER | 31 | -09-12 | 28 | -09-19 | 10-17 | 11-02 | 11-11 |
| PRIMGHAR | 30 | -09-12 | 25 | -09-18 | 10-16 | 10-31 | 11-10 |
| LOGAN | 30 | -09-12 | 28 | -09-13 | 10-17 | 11-02 | 11-11 |
| Iowa Drought Region 4 - Southwest | 32 | -09-12 | 26 | -09-28 | 10-19 | 11-03 | 11-13 |
| CHARLES-CITY | 32 | -09-12 | 28 | -09-20 | 10-16 | 11-02 | 11-11 |
| SPIRIT LAKE | 31 | -09-12 | 28 | -09-18 | 10-17 | 11-01 | 11-10 |
| CORNING | 32 | -09-12 | 27 | -09-21 | 10-17 | 11-02 | 11-13 |
| MARSHALLTOWN | 31 | -09-12 | 28 | -09-20 | 10-17 | 11-02 | 11-11 |
| WINTERSET | 31 | -09-12 | 26 | -09-20 | 10-19 | 11-07 | 11-21 |
| CHARITON | 32 | -09-12 | 28 | -09-20 | 10-17 | 11-05 | 11-21 |
| PERRY | 32 | -09-12 | 27 | -09-18 | 10-17 | 11-02 | 11-11 |
| AUDUBON | 30 | -09-12 | 27 | -09-19 | 10-17 | 11-01 | 11-10 |
| Iowa - Northwest Climate Division | 30 | -09-12 | 26 | -09-20 | 10-12 | 10-28 | 11-09 |
| Iowa - West Central Climate Division | 31 | -09-12 | 28 | -09-20 | 10-17 | 11-02 | 11-11 |
| COLUMBUS JUNCT 2 SSW | 31 | -09-12 | 28 | -09-20 | 10-24 | 11-08 | 11-22 |
| Iowa Drought Region 1 - Northwest | 30 | -09-12 | 28 | -09-19 | 10-12 | 10-31 | 11-10 |
| STORM-LAKE-2-E | 32 | -09-12 | 28 | -09-18 | 10-17 | 11-01 | 11-10 |
| Iowa - Southwest Climate Division | 32 | -09-13 | 26 | -09-28 | 10-19 | 11-06 | 11-21 |
| SIGOURNEY | 32 | -09-13 | 25 | -09-21 | 10-19 | 11-08 | 11-22 |
| CENTERVILLE | 31 | -09-13 | 28 | -09-22 | 10-25 | 11-10 | 11-22 |
| Iowa Average | 32 | -09-13 | 24 | -09-28 | 10-18 | 11-03 | 11-11 |
| MASON CITY MUNICIPAL AP | 31 | -09-13 | 26 | -09-15 | 10-09 | 10-31 | 11-07 |
| CLARINDA | 31 | -09-13 | 28 | -09-21 | 10-18 | 11-02 | 11-19 |
| BATTLE CREEK 3NE | 32 | -09-13 | 24 | -09-23 | 10-07 | 10-25 | 10-31 |
| OSKALOOSA | 31 | -09-13 | 27 | -09-20 | 10-19 | 11-08 | 11-21 |
| WASHINGTON | 30 | -09-13 | 28 | -09-23 | 10-24 | 11-08 | 11-22 |
| ESTHERVILLE MUNICIPAL AP | 31 | -09-13 | 28 | -09-15 | 10-10 | 10-26 | 11-10 |
| MOUNT-AYR | 32 | -09-13 | 28 | -09-19 | 10-19 | 11-05 | 11-21 |
| AMES-8-WSW | 31 | -09-13 | 26 | -09-21 | 10-18 | 11-02 | 11-12 |
| NORTHWOOD | 32 | -09-13 | 28 | -09-18 | 10-10 | 10-28 | 11-08 |
| Iowa - Northeast Climate Division | 32 | -09-13 | 26 | -09-26 | 10-17 | 11-02 | 11-11 |
| AMES 5 SE | 32 | -09-13 | 28 | -09-26 | 10-19 | 11-05 | 11-21 |
| Iowa Drought Region 3 - Northeast | 32 | -09-13 | 27 | -09-26 | 10-17 | 11-03 | 11-11 |
| SIOUX-CITY-WSO-AP | 30 | -09-13 | 25 | -09-22 | 10-17 | 11-02 | 11-10 |
| LOWDEN | 32 | -09-13 | 26 | -09-24 | 10-14 | 11-01 | 11-11 |
| Sioux City Area | 30 | -09-13 | 25 | -09-22 | 10-17 | 11-02 | 11-10 |
| Iowa - North Central Climate Division | 32 | -09-13 | 28 | -09-18 | 10-13 | 11-01 | 11-10 |
| MOUNT-PLEASANT | 32 | -09-13 | 28 | -09-24 | 10-25 | 11-10 | 11-22 |
| Ames Area | 31 | -09-13 | 26 | -09-21 | 10-17 | 11-02 | 11-11 |
| MANCHESTER-2 | 32 | -09-13 | 27 | -09-16 | 10-10 | 11-02 | 11-11 |
| VINTON | 32 | -09-13 | 28 | -09-21 | 10-17 | 11-03 | 11-12 |
| CLINTON-1 | 31 | -09-13 | 28 | -09-25 | 10-20 | 11-09 | 11-22 |
| Iowa City | 32 | -09-14 | 28 | -09-18 | 10-19 | 11-06 | 11-21 |
| OSAGE | 30 | -09-14 | 28 | -09-18 | 10-13 | 11-01 | 11-10 |
| Ottumwa | 32 | -09-15 | 23 | -09-28 | 10-24 | 11-09 | 11-22 |
| MARSHALLTOWN MUNICIPAL AP | 30 | -09-15 | 27 | -09-23 | 10-14 | 10-31 | 11-11 |
| CEDAR-RAPIDS-1 | 32 | -09-15 | 24 | -09-26 | 10-20 | 11-06 | 11-21 |
| Cedar Rapids Area | 31 | -09-15 | 28 | -09-24 | 10-18 | 11-05 | 11-19 |
| AMES MUNICIPAL AP | 31 | -09-15 | 27 | -09-30 | 10-14 | 10-31 | 11-11 |
| LITTLE SIOUX 2NW | 31 | -09-15 | 27 | -09-23 | 10-08 | 10-25 | 11-11 |
| OSCEOLA-3-WSW | 31 | -09-15 | 28 | -09-22 | 10-19 | 11-07 | 11-21 |
| Creston | 31 | -09-15 | 28 | -09-19 | 10-19 | 11-03 | 11-13 |
| Dubuque Airport | 32 | -09-15 | 28 | -09-20 | 10-16 | 11-03 | 11-13 |
| Cedar Rapids Airport | 31 | -09-15 | 28 | -09-24 | 10-18 | 11-05 | 11-19 |
| Dubuque Area | 32 | -09-15 | 28 | -09-20 | 10-19 | 11-06 | 11-21 |
| OELWEIN 1E | 32 | -09-15 | 28 | -10-05 | 10-14 | 10-28 | 11-11 |
| SHENANDOAH-1-NE | 32 | -09-16 | 28 | -09-20 | 10-24 | 11-07 | 11-21 |
| WAUKON | 32 | -09-16 | 25 | -09-25 | 10-13 | 11-01 | 11-10 |
| GREENFIELD | 32 | -09-17 | 27 | -09-22 | 10-19 | 11-08 | 11-21 |
| NEWTON | 32 | -09-18 | 23 | -09-28 | 10-20 | 11-06 | 11-21 |
| GUTTENBERG-L-AND-D-10 | 32 | -09-18 | 25 | -09-28 | 10-24 | 11-07 | 11-21 |
| Burlington Airport | 30 | -09-18 | 25 | -09-28 | 10-27 | 11-10 | 11-24 |
| Iowa - East Central Climate Division | 32 | -09-18 | 28 | -09-26 | 10-19 | 11-06 | 11-21 |
| Iowa - Central Climate Division | 31 | -09-18 | 28 | -09-22 | 10-17 | 11-03 | 11-11 |
| Lamoni | 32 | -09-18 | 27 | -09-28 | 10-24 | 11-08 | 11-21 |
| BEACONSFIELD | 27 | -09-19 | 27 | -09-19 | 10-19 | 11-07 | 11-20 |
| Allerton | 31 | -09-19 | 27 | -09-22 | 10-19 | 11-08 | 11-21 |
| Iowa - South Central Climate Division | 31 | -09-19 | 25 | -09-28 | 10-24 | 11-08 | 11-21 |
| IOWA CITY MUNICIPAL AP | 32 | -09-20 | 26 | -09-23 | 10-19 | 11-10 | 11-21 |
| Iowa Drought Region 5 - Southeast | 31 | -09-20 | 24 | -09-28 | 10-24 | 11-08 | 11-21 |
| Iowa - Southeast Climate Division | 32 | -09-20 | 25 | -09-28 | 10-25 | 11-09 | 11-22 |
| MUSCATINE | 29 | -09-20 | 23 | -09-28 | 10-24 | 11-10 | 11-21 |
| Donnellson | 31 | -09-20 | 25 | -09-28 | 10-25 | 11-10 | 11-22 |
| DUBUQUE-LOCK-AND-DAM | 31 | -09-20 | 24 | -09-30 | 10-25 | 11-10 | 11-22 |
| DES MOINES WSFO-JOHNSTON | 31 | -09-21 | 28 | -10-02 | 10-24 | 11-10 | 11-12 |
| RATHBUN DAM | 32 | -09-22 | 28 | -10-01 | 10-17 | 11-07 | 11-21 |
| Des Moines Airport | 31 | -09-22 | 26 | -09-28 | 10-24 | 11-08 | 11-21 |
| Fort Madison | 32 | -09-22 | 26 | -09-28 | 10-27 | 11-11 | 11-24 |
| Des Moines Area | 31 | -09-22 | 26 | -09-28 | 10-24 | 11-08 | 11-21 |
| DAVENPORT WFO | 30 | -09-23 | 27 | -10-05 | 10-16 | 11-01 | 11-11 |
| KEOKUK LOCK DAM 19 | 30 | -09-23 | 23 | -10-06 | 11-02 | 11-13 | 11-28 |
| OTTUMWA #1 | 32 | -09-23 | 26 | -10-02 | 10-16 | 11-10 | 11-21 |
| SIOUX CITY ANG | 31 | -09-23 | 20 | -10-02 | 10-08 | 10-27 | 11-10 |
| ANAMOSA 3 SSW | 30 | -09-24 | 26 | -10-16 | 10-15 | 11-01 | 11-12 |
| BURLINGTON | 32 | -09-26 | 28 | -10-02 | 10-28 | 11-11 | 11-27 |
| Le Claire L&D 14 | 32 | -09-26 | 28 | -09-28 | 10-28 | 11-11 | 11-24 |
| MUSCATINE 2N | 27 | -10-02 | 27 | -10-02 | 10-17 | 11-11 | 11-22 |
| HOLSTEIN 5 NNW | 30 | -10-02 | 28 | -10-12 | 10-08 | 10-25 | 10-31 |
| MAXON | 19 | {1893}-12-18 | 19 | {1893}-12-18 | 12-18 | 12-18 | 12-18 |
| MECHANICSVILLE | 23 | {1896}-12-18 | 23 | {1896}-12-18 | 12-18 | 12-18 | 12-18 |
| ATLANTIC NEAR | 16 | {1896}-12-18 | 16 | {1896}-12-18 | 12-18 | 12-18 | 12-18 |
| AMES EXPERIMENT STATION | 16 | {1896}-12-18 | 16 | {1896}-12-18 | 12-18 | 12-18 | 12-18 |
| SEYMOUR | 20 | {1896}-12-18 | 20 | {1896}-12-18 | 12-18 | 12-18 | 12-18 |
| REINBECK 2 W | 16 | {1896}-12-18 | 16 | {1896}-12-18 | 12-18 | 12-18 | 12-18 |
| GALVA | -19 | {1897,1901,1983}-12-18 | -19 | {1897,1901,1983}-12-18 | 12-18 | 12-18 | 12-18 |
| ODEBOLT | -15 | {1897,1901}-12-18 | -15 | {1897,1901}-12-18 | 12-18 | 12-18 | 12-18 |
| ODEBOLT 2 | -15 | {1897,1901}-12-18 | -15 | {1897,1901}-12-18 | 12-18 | 12-18 | 12-18 |
| COLLEGE SPRINGS | -10 | {1897,1901}-12-18 | -10 | {1897,1901}-12-18 | 12-18 | 12-18 | 12-18 |
| AFTON | -10 | {1897,1901}-12-18 | -10 | {1897,1901}-12-18 | 12-18 | 12-18 | 12-18 |
| OVID | -11 | {1897,1901}-12-18 | -11 | {1897,1901}-12-18 | 12-18 | 12-18 | 12-18 |
| VILLISCA | -19 | {1897}-12-18 | -19 | {1897}-12-18 | 12-18 | 12-18 | 12-18 |
| WAUKEE | -14 | {1897}-12-18 | -14 | {1897}-12-18 | 12-18 | 12-18 | 12-18 |
| WHITTEN | -14 | {1897}-12-18 | -14 | {1897}-12-18 | 12-18 | 12-18 | 12-18 |
| OGDEN | -22 | {1897}-12-18 | -22 | {1897}-12-18 | 12-18 | 12-18 | 12-18 |
| NORTH MCGREGOR | -12 | {1897}-12-18 | -12 | {1897}-12-18 | 12-18 | 12-18 | 12-18 |
| NEOLA | -16 | {1897}-12-18 | -16 | {1897}-12-18 | 12-18 | 12-18 | 12-18 |
| MOUNT VERNON | -12 | {1897}-12-18 | -12 | {1897}-12-18 | 12-18 | 12-18 | 12-18 |
| MOUNT VERNON | -11 | {1897}-12-18 | -11 | {1897}-12-18 | 12-18 | 12-18 | 12-18 |
| MOOAR | -5 | {1897}-12-18 | -5 | {1897}-12-18 | 12-18 | 12-18 | 12-18 |
| MONTICELLO | -15 | {1897}-12-18 | -15 | {1897}-12-18 | 12-18 | 12-18 | 12-18 |
| MADRID | -15 | {1897}-12-18 | -15 | {1897}-12-18 | 12-18 | 12-18 | 12-18 |
| LARCHWOOD | -18 | {1897}-12-18 | -18 | {1897}-12-18 | 12-18 | 12-18 | 12-18 |
| IOWA CITY (MRS HOBBY) | -8 | {1897}-12-18 | -8 | {1897}-12-18 | 12-18 | 12-18 | 12-18 |
| HEDRICK | -11 | {1897}-12-18 | -11 | {1897}-12-18 | 12-18 | 12-18 | 12-18 |
| HAWKEYE | -13 | {1897}-12-18 | -13 | {1897}-12-18 | 12-18 | 12-18 | 12-18 |
| GLENWOOD 5 ESE | -13 | {1897}-12-18 | -13 | {1897}-12-18 | 12-18 | 12-18 | 12-18 |
| GLENWOOD | -19 | {1897}-12-18 | -19 | {1897}-12-18 | 12-18 | 12-18 | 12-18 |
| GLADBROOK | -14 | {1897}-12-18 | -14 | {1897}-12-18 | 12-18 | 12-18 | 12-18 |
| GARDEN GROVE | 5 | {1897}-12-18 | 5 | {1897}-12-18 | 12-18 | 12-18 | 12-18 |
| FREDERICKSBURG | -14 | {1897}-12-18 | -14 | {1897}-12-18 | 12-18 | 12-18 | 12-18 |
| FONDA | -18 | {1897}-12-18 | -18 | {1897}-12-18 | 12-18 | 12-18 | 12-18 |
| Eldora | -21 | {1897}-12-18 | -21 | {1897}-12-18 | 12-18 | 12-18 | 12-18 |
| DOWS | -19 | {1897}-12-18 | -19 | {1897}-12-18 | 12-18 | 12-18 | 12-18 |
| DE SOTO | -18 | {1897}-12-18 | -18 | {1897}-12-18 | 12-18 | 12-18 | 12-18 |
| DES MOINES MILLMAN | -14 | {1897}-12-18 | -14 | {1897}-12-18 | 12-18 | 12-18 | 12-18 |
| Des Moines SE 6th | -13 | {1897}-12-18 | -13 | {1897}-12-18 | 12-18 | 12-18 | 12-18 |
| COUNCIL BLUFFS 6 NE | -16 | {1897}-12-18 | -16 | {1897}-12-18 | 12-18 | 12-18 | 12-18 |
| AMES SOUTHEAST | -14 | {1897}-12-18 | -14 | {1897}-12-18 | 12-18 | 12-18 | 12-18 |
| AMANA | -14 | {1897}-12-18 | -14 | {1897}-12-18 | 12-18 | 12-18 | 12-18 |
| ALTA NEAR | -19 | {1897}-12-18 | -19 | {1897}-12-18 | 12-18 | 12-18 | 12-18 |
| THURMAN | -19 | {1897}-12-18 | -19 | {1897}-12-18 | 12-18 | 12-18 | 12-18 |
| TARA | -8 | {1897}-12-18 | -8 | {1897}-12-18 | 12-18 | 12-18 | 12-18 |
| SIOUX CITY | -15 | {1897}-12-18 | -15 | {1897}-12-18 | 12-18 | 12-18 | 12-18 |
| SCRANTON | -17 | {1897}-12-18 | -17 | {1897}-12-18 | 12-18 | 12-18 | 12-18 |
| ST CHARLES | -12 | {1897}-12-18 | -12 | {1897}-12-18 | 12-18 | 12-18 | 12-18 |
| PORTSMOUTH | -18 | {1897}-12-18 | -18 | {1897}-12-18 | 12-18 | 12-18 | 12-18 |
| PIONEER | 14 | {1898}-12-18 | 14 | {1898}-12-18 | 12-18 | 12-18 | 12-18 |
| CHILLICOTHE | 25 | {1899}-12-18 | 25 | {1899}-12-18 | 12-18 | 12-18 | 12-18 |
| BATAVIA | 28 | {1899}-12-18 | 28 | {1899}-12-18 | 12-18 | 12-18 | |
| MURRAY | -10 | {1901,1897}-12-18 | -10 | {1901,1897}-12-18 | 12-18 | 12-18 | 12-18 |
| MILLERTON | -11 | {1901,1897}-12-18 | -11 | {1901,1897}-12-18 | 12-18 | 12-18 | 12-18 |
| GALVA | -19 | {1901,1897}-12-18 | -19 | {1901,1897}-12-18 | 12-18 | 12-18 | 12-18 |
| WEST BEND | -17 | {1901,1945}-12-18 | -17 | {1901,1945}-12-18 | 12-18 | 12-18 | 12-18 |
| WEST BRANCH | -10 | {1901}-12-18 | -10 | {1901}-12-18 | 12-18 | 12-18 | 12-18 |
| WEST UNION | -15 | {1901}-12-18 | -15 | {1901}-12-18 | 12-18 | 12-18 | 12-18 |
| WHAT CHEER | -11 | {1901}-12-18 | -11 | {1901}-12-18 | 12-18 | 12-18 | 12-18 |
| NORTHBORO | -8 | {1901}-12-18 | -8 | {1901}-12-18 | 12-18 | 12-18 | 12-18 |
| MELROSE | -10 | {1901}-12-18 | -10 | {1901}-12-18 | 12-18 | 12-18 | 12-18 |
| LARRABEE | -20 | {1901}-12-18 | -20 | {1901}-12-18 | 12-18 | 12-18 | 12-18 |
| LACONA | -11 | {1901}-12-18 | -11 | {1901}-12-18 | 12-18 | 12-18 | 12-18 |
| HOPEVILLE | -11 | {1901}-12-18 | -11 | {1901}-12-18 | 12-18 | 12-18 | 12-18 |
| GRINNELL NEAR | -15 | {1901}-12-18 | -15 | {1901}-12-18 | 12-18 | 12-18 | 12-18 |
| GREENE | -18 | {1901}-12-18 | -18 | {1901}-12-18 | 12-18 | 12-18 | 12-18 |
| FRUITLAND | -10 | {1901}-12-18 | -10 | {1901}-12-18 | 12-18 | 12-18 | 12-18 |
| EMERSON 4 ENE | -9 | {1901}-12-18 | -9 | {1901}-12-18 | 12-18 | 12-18 | 12-18 |
| ELDON | -10 | {1901}-12-18 | -10 | {1901}-12-18 | 12-18 | 12-18 | 12-18 |
| DAVENPORT | -8 | {1901}-12-18 | -8 | {1901}-12-18 | 12-18 | 12-18 | 12-18 |
| DANVILLE | -10 | {1901}-12-18 | -10 | {1901}-12-18 | 12-18 | 12-18 | 12-18 |
| CUMBERLAND | -11 | {1901}-12-18 | -11 | {1901}-12-18 | 12-18 | 12-18 | 12-18 |
| CLEAR LAKE | -19 | {1901}-12-18 | -19 | {1901}-12-18 | 12-18 | 12-18 | 12-18 |
| CARSON 3NNE | -10 | {1901}-12-18 | -10 | {1901}-12-18 | 12-18 | 12-18 | 12-18 |
| BUCKINGHAM | -13 | {1901}-12-18 | -13 | {1901}-12-18 | 12-18 | 12-18 | 12-18 |
| BONAPARTE 5 NE | -10 | {1901}-12-18 | -10 | {1901}-12-18 | 12-18 | 12-18 | 12-18 |
| BELKNAP | -10 | {1901}-12-18 | -10 | {1901}-12-18 | 12-18 | 12-18 | 12-18 |
| BANCROFT | -17 | {1901}-12-18 | -17 | {1901}-12-18 | 12-18 | 12-18 | 12-18 |
| ALTA | -17 | {1901}-12-18 | -17 | {1901}-12-18 | 12-18 | 12-18 | 12-18 |
| WOODBURN | -10 | {1901}-12-18 | -10 | {1901}-12-18 | 12-18 | 12-18 | 12-18 |
| STUART | -12 | {1901}-12-18 | -12 | {1901}-12-18 | 12-18 | 12-18 | 12-18 |
| STOCKPORT | -10 | {1901}-12-18 | -10 | {1901}-12-18 | 12-18 | 12-18 | 12-18 |
| RUTHVEN | -16 | {1901}-12-18 | -16 | {1901}-12-18 | 12-18 | 12-18 | 12-18 |
| RIDGEWAY | -18 | {1901}-12-18 | -18 | {1901}-12-18 | 12-18 | 12-18 | 12-18 |
| PLOVER | -20 | {1901}-12-18 | -20 | {1901}-12-18 | 12-18 | 12-18 | 12-18 |
| HANLONTOWN | 9 | {1902}-12-18 | 9 | {1902}-12-18 | 12-18 | 12-18 | 12-18 |
| CHESTER | 8 | {1902}-12-18 | 8 | {1902}-12-18 | 12-18 | 12-18 | 12-18 |
| FLORENCE | 16 | {1904}-12-18 | 16 | {1904}-12-18 | 12-18 | 12-18 | 12-18 |
| NEVADA | -2 | {1906}-12-18 | -2 | {1906}-12-18 | 12-18 | 12-18 | 12-18 |
| INWOOD 2 SW | -20 | {1909,1922,1963}-12-18 | -20 | {1909,1922,1963}-12-18 | 12-18 | 12-18 | 12-18 |
| LITTLE SIOUX | -15 | {1909}-12-18 | -15 | {1909}-12-18 | 12-18 | 12-18 | 12-18 |
| ELLIOTT | -10 | {1909}-12-18 | -10 | {1909}-12-18 | 12-18 | 12-18 | 12-18 |
| WILTON JUNCTION | -10 | {1909}-12-18 | -10 | {1909}-12-18 | 12-18 | 12-18 | 12-18 |
| PACIFIC JUNCTION | -12 | {1909}-12-18 | -12 | {1909}-12-18 | 12-18 | 12-18 | 12-18 |
| LENOX | -16 | {1914}-12-18 | -16 | {1914}-12-18 | 12-18 | 12-18 | 12-18 |
| MATLOCK | -4 | {1916}-12-18 | -4 | {1916}-12-18 | 12-18 | 12-18 | 12-18 |
| OTTUMWA 1 WSW | -8 | {1922,1897}-12-18 | -8 | {1922,1897}-12-18 | 12-18 | 12-18 | 12-18 |
| INDEPENDENCE | -20 | {1922,1983}-12-18 | -20 | {1922,1983}-12-18 | 12-18 | 12-18 | 12-18 |
| WATERLOO | -18 | {1922}-12-18 | -18 | {1922}-12-18 | 12-18 | 12-18 | 12-18 |
| WESCOTT | -6 | {1922}-12-18 | -6 | {1922}-12-18 | 12-18 | 12-18 | 12-18 |
| OLIN | -19 | {1922}-12-18 | -19 | {1922}-12-18 | 12-18 | 12-18 | 12-18 |
| NORA SPRINGS | -18 | {1922}-12-18 | -18 | {1922}-12-18 | 12-18 | 12-18 | 12-18 |
| MONROE | -9 | {1922}-12-18 | -9 | {1922}-12-18 | 12-18 | 12-18 | 12-18 |
| LE CLAIRE | -10 | {1922}-12-18 | -10 | {1922}-12-18 | 12-18 | 12-18 | 12-18 |
| FAIRPORT | -10 | {1922}-12-18 | -10 | {1922}-12-18 | 12-18 | 12-18 | 12-18 |
| EARLHAM | -9 | {1922}-12-18 | -9 | {1922}-12-18 | 12-18 | 12-18 | 12-18 |
| DUBUQUE RIVER | -14 | {1922}-12-18 | -14 | {1922}-12-18 | 12-18 | 12-18 | 12-18 |
| DECORAH 2 S | -25 | {1922}-12-18 | -25 | {1922}-12-18 | 12-18 | 12-18 | 12-18 |
| DAVENPORT 2 | -10 | {1922}-12-18 | -10 | {1922}-12-18 | 12-18 | 12-18 | 12-18 |
| CEDAR RAPIDS 2 | -13 | {1922}-12-18 | -13 | {1922}-12-18 | 12-18 | 12-18 | 12-18 |
| BOONE 3 WNW | -12 | {1922}-12-18 | -12 | {1922}-12-18 | 12-18 | 12-18 | 12-18 |
| BELMOND | -18 | {1922}-12-18 | -18 | {1922}-12-18 | 12-18 | 12-18 | 12-18 |
| BAXTER | -15 | {1922}-12-18 | -15 | {1922}-12-18 | 12-18 | 12-18 | 12-18 |
| AMES 3 SW | -18 | {1922}-12-18 | -18 | {1922}-12-18 | 12-18 | 12-18 | 12-18 |
| PELLA 1S | -17 | {1922}-12-18 | -17 | {1922}-12-18 | 12-18 | 12-18 | 12-18 |
| RED OAK 10 SW | -3 | {1924}-12-18 | -3 | {1924}-12-18 | 12-18 | 12-18 | 12-18 |
| WEVER | 14 | {1929}-12-18 | 14 | {1929}-12-18 | 12-18 | 12-18 | 12-18 |
| MARATHON | -7 | {1929}-12-18 | -7 | {1929}-12-18 | 12-18 | 12-18 | 12-18 |
| KEOKUK NO 2 | -2 | {1932}-12-18 | -2 | {1932}-12-18 | 12-18 | 12-18 | 12-18 |
| ORLEANS | 13 | {1935}-12-18 | 13 | {1935}-12-18 | 12-18 | 12-18 | 12-18 |
| CLARINDA WALNUT CREEK | 15 | {1940}-12-18 | 15 | {1940}-12-18 | 12-18 | 12-18 | 12-18 |
| CLARINDA TARKIO CREEK | 15 | {1940}-12-18 | 15 | {1940}-12-18 | 12-18 | 12-18 | 12-18 |
| CLARINDA PLUM CREEK | 15 | {1940}-12-18 | 15 | {1940}-12-18 | 12-18 | 12-18 | 12-18 |
| STACEYVILLE | 28 | {1941}-12-18 | 28 | {1941}-12-18 | 12-18 | 12-18 | |
| TERRIL | 6 | {1942}-12-18 | 6 | {1942}-12-18 | 12-18 | 12-18 | 12-18 |
| DENISON SCS | 2 | {1944}-12-18 | 2 | {1944}-12-18 | 12-18 | 12-18 | 12-18 |
| TINGLEY | -5 | {1945,1944}-12-18 | -5 | {1945,1944}-12-18 | 12-18 | 12-18 | 12-18 |
| WAVERLY | -20 | {1945}-12-18 | -20 | {1945}-12-18 | 12-18 | 12-18 | 12-18 |
| MONDAMIN | -4 | {1945}-12-18 | -4 | {1945}-12-18 | 12-18 | 12-18 | 12-18 |
| LAKE VIEW | -7 | {1945}-12-18 | -7 | {1945}-12-18 | 12-18 | 12-18 | 12-18 |
| HARTLEY 3 S | -13 | {1945}-12-18 | -13 | {1945}-12-18 | 12-18 | 12-18 | 12-18 |
| DEXTER | -4 | {1945}-12-18 | -4 | {1945}-12-18 | 12-18 | 12-18 | 12-18 |
| DELAWARE 3 WSW | -18 | {1945}-12-18 | -18 | {1945}-12-18 | 12-18 | 12-18 | 12-18 |
| CUSHING | -9 | {1945}-12-18 | -9 | {1945}-12-18 | 12-18 | 12-18 | 12-18 |
| ANTHON | -7 | {1945}-12-18 | -7 | {1945}-12-18 | 12-18 | 12-18 | 12-18 |
| WOODBINE | -3 | {1945}-12-18 | -3 | {1945}-12-18 | 12-18 | 12-18 | 12-18 |
| STATE CENTER | -9 | {1945}-12-18 | -9 | {1945}-12-18 | 12-18 | 12-18 | 12-18 |
| SLOAN | -6 | {1945}-12-18 | -6 | {1945}-12-18 | 12-18 | 12-18 | 12-18 |
| MUSCATINE 6 N | 27 | {1948}-12-18 | 27 | {1948}-12-18 | 12-18 | 12-18 | |
| MARSHALLTOWN 1 | 22 | {1948}-12-18 | 22 | {1948}-12-18 | 12-18 | 12-18 | 12-18 |
| MARSHALLTOWN #2 | 25 | {1949}-12-18 | 25 | {1949}-12-18 | 12-18 | 12-18 | 12-18 |
| CLARENCE | -9 | {1950,1963}-12-18 | -9 | {1950,1963}-12-18 | 12-18 | 12-18 | 12-18 |
| STANTON 4N | 5 | {1950}-12-18 | 5 | {1950}-12-18 | 12-18 | 12-18 | 12-18 |
| WHEATLAND | -9 | {1950}-12-18 | -9 | {1950}-12-18 | 12-18 | 12-18 | 12-18 |
| OASIS 1 NW | -9 | {1950}-12-18 | -9 | {1950}-12-18 | 12-18 | 12-18 | 12-18 |
| NASHUA 2 NW | -17 | {1950}-12-18 | -17 | {1950}-12-18 | 12-18 | 12-18 | 12-18 |
| MOVILLE | 7 | {1950}-12-18 | 7 | {1950}-12-18 | 12-18 | 12-18 | 12-18 |
| MORSE 4 SSW | -9 | {1950}-12-18 | -9 | {1950}-12-18 | 12-18 | 12-18 | 12-18 |
| MORSE 1 NE | -10 | {1950}-12-18 | -10 | {1950}-12-18 | 12-18 | 12-18 | 12-18 |
| MORSE | -10 | {1950}-12-18 | -10 | {1950}-12-18 | 12-18 | 12-18 | 12-18 |
| MONONA | -13 | {1950}-12-18 | -13 | {1950}-12-18 | 12-18 | 12-18 | 12-18 |
| MONMOUTH 4 SW | -13 | {1950}-12-18 | -13 | {1950}-12-18 | 12-18 | 12-18 | 12-18 |
| MARION 4 NE | -11 | {1950}-12-18 | -11 | {1950}-12-18 | 12-18 | 12-18 | 12-18 |
| KEOKUK LOCK & DAM 19 | -3 | {1950}-12-18 | -3 | {1950}-12-18 | 12-18 | 12-18 | 12-18 |
| IOWA CITY RALSTON CREEK | -10 | {1950}-12-18 | -10 | {1950}-12-18 | 12-18 | 12-18 | 12-18 |
| IOWA CITY RALSTON CREEK | -10 | {1950}-12-18 | -10 | {1950}-12-18 | 12-18 | 12-18 | 12-18 |
| IOWA CITY RALSTON CREEK | -9 | {1950}-12-18 | -9 | {1950}-12-18 | 12-18 | 12-18 | 12-18 |
| IOWA CITY RALSTON CREEK | -9 | {1950}-12-18 | -9 | {1950}-12-18 | 12-18 | 12-18 | 12-18 |
| IOWA CITY RALSTON CREEK | -9 | {1950}-12-18 | -9 | {1950}-12-18 | 12-18 | 12-18 | 12-18 |
| HORNICK 5S | 8 | {1950}-12-18 | 8 | {1950}-12-18 | 12-18 | 12-18 | 12-18 |
| HINTON 4 W | 6 | {1950}-12-18 | 6 | {1950}-12-18 | 12-18 | 12-18 | 12-18 |
| DUNBAR 2 NE | -9 | {1950}-12-18 | -9 | {1950}-12-18 | 12-18 | 12-18 | 12-18 |
| COUNCIL BLUFFS 6 NNE | 10 | {1950}-12-18 | 10 | {1950}-12-18 | 12-18 | 12-18 | 12-18 |
| BEAVER 2 NE | -1 | {1950}-12-18 | -1 | {1950}-12-18 | 12-18 | 12-18 | 12-18 |
| TABOR 6 NNW | 11 | {1950}-12-18 | 11 | {1950}-12-18 | 12-18 | 12-18 | 12-18 |
| SOLDIER | 8 | {1950}-12-18 | 8 | {1950}-12-18 | 12-18 | 12-18 | 12-18 |
| SHEFFIELD 3 NW | -16 | {1950}-12-18 | -16 | {1950}-12-18 | 12-18 | 12-18 | 12-18 |
| SARATOGA 2 E | -24 | {1950}-12-18 | -24 | {1950}-12-18 | 12-18 | 12-18 | 12-18 |
| REMSEN | 4 | {1950}-12-18 | 4 | {1950}-12-18 | 12-18 | 12-18 | 12-18 |
| OTO | -7 | {1951,1945}-12-18 | -7 | {1951,1945}-12-18 | 12-18 | 12-18 | 12-18 |
| MISSOURI VALLEY 1 NNE | -8 | {1951}-12-18 | -8 | {1951}-12-18 | 12-18 | 12-18 | 12-18 |
| RIVERTON | -3 | {1951}-12-18 | -3 | {1951}-12-18 | 12-18 | 12-18 | 12-18 |
| MERRILL 4 WSW | -14 | {1963,1909}-12-18 | -14 | {1963,1909}-12-18 | 12-18 | 12-18 | 12-18 |
| OTTUMWA | -8 | {1963,1922}-12-18 | -8 | {1963,1922}-12-18 | 12-18 | 12-18 | 12-18 |
| KEOSAUQUA 2 | -8 | {1963,1950}-12-18 | -8 | {1963,1950}-12-18 | 12-18 | 12-18 | 12-18 |
| NORWICH EXPERIMENT FARM | -11 | {1963}-12-18 | -11 | {1963}-12-18 | 12-18 | 12-18 | 12-18 |
| MCGREGOR | -9 | {1963}-12-18 | -9 | {1963}-12-18 | 12-18 | 12-18 | 12-18 |
| LAKE CITY | -13 | {1963}-12-18 | -13 | {1963}-12-18 | 12-18 | 12-18 | 12-18 |
| GLENWOOD 8 SSE | -8 | {1963}-12-18 | -8 | {1963}-12-18 | 12-18 | 12-18 | 12-18 |
| BARTLETT 5 E | -8 | {1963}-12-18 | -8 | {1963}-12-18 | 12-18 | 12-18 | 12-18 |
| ALBIA PASTURE IMP FARM | -10 | {1963}-12-18 | -10 | {1963}-12-18 | 12-18 | 12-18 | 12-18 |
| ADEL 1 SE | -12 | {1963}-12-18 | -12 | {1963}-12-18 | 12-18 | 12-18 | 12-18 |
| WOODWARD 7 N | -12 | {1963}-12-18 | -12 | {1963}-12-18 | 12-18 | 12-18 | 12-18 |
| HAMBURG | -1 | {1975}-12-18 | -1 | {1975}-12-18 | 12-18 | 12-18 | 12-18 |
| CENTERVILLE 5 E | 0 | {1975}-12-18 | 0 | {1975}-12-18 | 12-18 | 12-18 | 12-18 |
| SIOUX CITY 8 N | -16 | {1981}-12-18 | -16 | {1981}-12-18 | 12-18 | 12-18 | 12-18 |
| SIDNEY | -15 | {1981}-12-18 | -15 | {1981}-12-18 | 12-18 | 12-18 | 12-18 |
| TRACY 1 NE | -14 | {1983,1985,2016}-12-18 | -14 | {1983,1985,2016}-12-18 | 12-18 | 12-18 | 12-18 |
| WALFORD 2 SE | -17 | {1983,1985}-12-18 | -17 | {1983,1985}-12-18 | 12-18 | 12-18 | 12-18 |
| NORTH ENGLISH | -16 | {1983,1985}-12-18 | -16 | {1983,1985}-12-18 | 12-18 | 12-18 | 12-18 |
| HARLAN | -17 | {1983,1985}-12-18 | -17 | {1983,1985}-12-18 | 12-18 | 12-18 | 12-18 |
| CHARITON 5SSE | -13 | {1983,1985}-12-18 | -13 | {1983,1985}-12-18 | 12-18 | 12-18 | 12-18 |
| TIPTON | -18 | {1983,1985}-12-18 | -18 | {1983,1985}-12-18 | 12-18 | 12-18 | 12-18 |
| PAULLINA | -17 | {1983,1985}-12-18 | -17 | {1983,1985}-12-18 | 12-18 | 12-18 | 12-18 |
| READ OAK # 2 | -14 | {1983,2016}-12-18 | -14 | {1983,2016}-12-18 | 12-18 | 12-18 | 12-18 |
| WILLIAMS | -20 | {1983}-12-18 | -20 | {1983}-12-18 | 12-18 | 12-18 | 12-18 |
| TRAER | -19 | {1983}-12-18 | -19 | {1983}-12-18 | 12-18 | 12-18 | 12-18 |
| TRIPOLI-4-N | -22 | {1983}-12-18 | -22 | {1983}-12-18 | 12-18 | 12-18 | 12-18 |
| TURIN 4S | -18 | {1983}-12-18 | -18 | {1983}-12-18 | 12-18 | 12-18 | 12-18 |
| TURIN 4 SSW | -18 | {1983}-12-18 | -18 | {1983}-12-18 | 12-18 | 12-18 | 12-18 |
| WAUCOMA 1WNW | -24 | {1983}-12-18 | -24 | {1983}-12-18 | 12-18 | 12-18 | 12-18 |
| BUCKEYE | -20 | {1983}-12-18 | -20 | {1983}-12-18 | 12-18 | 12-18 | 12-18 |
| OELWEIN-2-S | -20 | {1983}-12-18 | -20 | {1983}-12-18 | 12-18 | 12-18 | 12-18 |
| OCHEYEDAN | -21 | {1983}-12-18 | -21 | {1983}-12-18 | 12-18 | 12-18 | 12-18 |
| MERRILL | -20 | {1983}-12-18 | -20 | {1983}-12-18 | 12-18 | 12-18 | 12-18 |
| MARBLE ROCK | -25 | {1983}-12-18 | -25 | {1983}-12-18 | 12-18 | 12-18 | 12-18 |
| MAPLETON | -18 | {1983}-12-18 | -18 | {1983}-12-18 | 12-18 | 12-18 | 12-18 |
| LOGAN NO 2 | -17 | {1983}-12-18 | -17 | {1983}-12-18 | 12-18 | 12-18 | 12-18 |
| LANSING | -24 | {1983}-12-18 | -24 | {1983}-12-18 | 12-18 | 12-18 | 12-18 |
| KILLDUFF | -15 | {1983}-12-18 | -15 | {1983}-12-18 | 12-18 | 12-18 | 12-18 |
| KENNEBEC | -18 | {1983}-12-18 | -18 | {1983}-12-18 | 12-18 | 12-18 | 12-18 |
| JEWELL | -19 | {1983}-12-18 | -19 | {1983}-12-18 | 12-18 | 12-18 | 12-18 |
| IRWIN 3 ESE | -17 | {1983}-12-18 | -17 | {1983}-12-18 | 12-18 | 12-18 | 12-18 |
| INDIANOLA-2-SSW | -16 | {1983}-12-18 | -16 | {1983}-12-18 | 12-18 | 12-18 | 12-18 |
| HUMBOLDT-2 | -24 | {1983}-12-18 | -24 | {1983}-12-18 | 12-18 | 12-18 | 12-18 |
| HUBBARD | -20 | {1983}-12-18 | -20 | {1983}-12-18 | 12-18 | 12-18 | 12-18 |
| HAWARDEN | -28 | {1983}-12-18 | -28 | {1983}-12-18 | 12-18 | 12-18 | 12-18 |
| HAVERHILL | -17 | {1983}-12-18 | -17 | {1983}-12-18 | 12-18 | 12-18 | 12-18 |
| HARCOURT 2ENE | -19 | {1983}-12-18 | -19 | {1983}-12-18 | 12-18 | 12-18 | 12-18 |
| HANCOCK | -16 | {1983}-12-18 | -16 | {1983}-12-18 | 12-18 | 12-18 | 12-18 |
| HAMBURG | -13 | {1983}-12-18 | -13 | {1983}-12-18 | 12-18 | 12-18 | 12-18 |
| GILMAN | -17 | {1983}-12-18 | -17 | {1983}-12-18 | 12-18 | 12-18 | 12-18 |
| GARWIN | -18 | {1983}-12-18 | -18 | {1983}-12-18 | 12-18 | 12-18 | 12-18 |
| EDDYVILLE | -14 | {1983}-12-18 | -14 | {1983}-12-18 | 12-18 | 12-18 | 12-18 |
| DUMONT | -24 | {1983}-12-18 | -24 | {1983}-12-18 | 12-18 | 12-18 | 12-18 |
| DORCHESTER | -26 | {1983}-12-18 | -26 | {1983}-12-18 | 12-18 | 12-18 | 12-18 |
| DAVENPORT LOCK & DAM 15 | -13 | {1983}-12-18 | -13 | {1983}-12-18 | 12-18 | 12-18 | 12-18 |
| CRESCO-1-NE | -28 | {1983}-12-18 | -28 | {1983}-12-18 | 12-18 | 12-18 | 12-18 |
| CORRECTIONVILLE 1 SW | -18 | {1983}-12-18 | -18 | {1983}-12-18 | 12-18 | 12-18 | 12-18 |
| CORALVILLE DAM | -20 | {1983}-12-18 | -20 | {1983}-12-18 | 12-18 | 12-18 | 12-18 |
| COON RAPIDS | -17 | {1983}-12-18 | -17 | {1983}-12-18 | 12-18 | 12-18 | 12-18 |
| CONRAD | -19 | {1983}-12-18 | -19 | {1983}-12-18 | 12-18 | 12-18 | 12-18 |
| CLUTIER | -18 | {1983}-12-18 | -18 | {1983}-12-18 | 12-18 | 12-18 | 12-18 |
| CLINTON 2 | -14 | {1983}-12-18 | -14 | {1983}-12-18 | 12-18 | 12-18 | 12-18 |
| CLARION | -23 | {1983}-12-18 | -23 | {1983}-12-18 | 12-18 | 12-18 | 12-18 |
| CEDAR FALLS | -22 | {1983}-12-18 | -22 | {1983}-12-18 | 12-18 | 12-18 | 12-18 |
| BROOKLYN | -17 | {1983}-12-18 | -17 | {1983}-12-18 | 12-18 | 12-18 | 12-18 |
| BEDFORD-1-NNW | -16 | {1983}-12-18 | -16 | {1983}-12-18 | 12-18 | 12-18 | 12-18 |
| Ankeny | -19 | {1983}-12-18 | -19 | {1983}-12-18 | 12-18 | 12-18 | 12-18 |
| ANAMOSA-1-WNW | -16 | {1983}-12-18 | -16 | {1983}-12-18 | 12-18 | 12-18 | 12-18 |
| ZEARING | -19 | {1983}-12-18 | -19 | {1983}-12-18 | 12-18 | 12-18 | 12-18 |
| TITONKA | -20 | {1983}-12-18 | -20 | {1983}-12-18 | 12-18 | 12-18 | 12-18 |
| STRAWBERRY POINT | -20 | {1983}-12-18 | -20 | {1983}-12-18 | 12-18 | 12-18 | 12-18 |
| STEAMBOAT ROCK | -21 | {1983}-12-18 | -21 | {1983}-12-18 | 12-18 | 12-18 | 12-18 |
| SPILLVILLE | -25 | {1983}-12-18 | -25 | {1983}-12-18 | 12-18 | 12-18 | 12-18 |
| SIOUX CITY PERRY CREEK | -19 | {1983}-12-18 | -19 | {1983}-12-18 | 12-18 | 12-18 | 12-18 |
| SHELL ROCK 1 SW | -23 | {1983}-12-18 | -23 | {1983}-12-18 | 12-18 | 12-18 | 12-18 |
| SHELBY | -17 | {1983}-12-18 | -17 | {1983}-12-18 | 12-18 | 12-18 | 12-18 |
| ST ANSGAR | -25 | {1983}-12-18 | -25 | {1983}-12-18 | 12-18 | 12-18 | 12-18 |
| RHODES 3E | -17 | {1983}-12-18 | -17 | {1983}-12-18 | 12-18 | 12-18 | 12-18 |
| RANDOLPH | -14 | {1983}-12-18 | -14 | {1983}-12-18 | 12-18 | 12-18 | 12-18 |
| PROMISE CITY 6 NW | -13 | {1983}-12-18 | -13 | {1983}-12-18 | 12-18 | 12-18 | 12-18 |
| POPEJOY 1S | -21 | {1983}-12-18 | -21 | {1983}-12-18 | 12-18 | 12-18 | 12-18 |
| PISGAH | -17 | {1983}-12-18 | -17 | {1983}-12-18 | 12-18 | 12-18 | 12-18 |
| PARKERSBURG | -22 | {1983}-12-18 | -22 | {1983}-12-18 | 12-18 | 12-18 | 12-18 |
| BLOOMFIELD | -13 | {1985,1963}-12-18 | -13 | {1985,1963}-12-18 | 12-18 | 12-18 | 12-18 |
| REDFIELD 2 E | -15 | {1985,1983,2016}-12-18 | -15 | {1985,1983,2016}-12-18 | 12-18 | 12-18 | 12-18 |
| MONTEZUMA 1 W | -16 | {1985,1983}-12-18 | -16 | {1985,1983}-12-18 | 12-18 | 12-18 | 12-18 |
| INDEPENDENCE-2-W | -20 | {1985,1983}-12-18 | -20 | {1985,1983}-12-18 | 12-18 | 12-18 | 12-18 |
| IDA GROVE 5NW | -23 | {1985,1983}-12-18 | -23 | {1985,1983}-12-18 | 12-18 | 12-18 | 12-18 |
| DERBY | -13 | {1985,1983}-12-18 | -13 | {1985,1983}-12-18 | 12-18 | 12-18 | 12-18 |
| BRIGHTON | -14 | {1985,1983}-12-18 | -14 | {1985,1983}-12-18 | 12-18 | 12-18 | 12-18 |
| Wapello | -16 | {1985}-12-18 | -16 | {1985}-12-18 | 12-18 | 12-18 | 12-18 |
| ONAWA | -22 | {1985}-12-18 | -22 | {1985}-12-18 | 12-18 | 12-18 | 12-18 |
| MUSCATINE 2 | -14 | {1985}-12-18 | -14 | {1985}-12-18 | 12-18 | 12-18 | 12-18 |
| MONTICELLO | -18 | {1985}-12-18 | -18 | {1985}-12-18 | 12-18 | 12-18 | 12-18 |
| LEON 6 ESE | -18 | {1985}-12-18 | -18 | {1985}-12-18 | 12-18 | 12-18 | 12-18 |
| KNOXVILLE | -15 | {1985}-12-18 | -15 | {1985}-12-18 | 12-18 | 12-18 | 12-18 |
| DE WITT | -16 | {1985}-12-18 | -16 | {1985}-12-18 | 12-18 | 12-18 | 12-18 |
| CORYDON 8 W | -17 | {1985}-12-18 | -17 | {1985}-12-18 | 12-18 | 12-18 | 12-18 |
| COLO | -21 | {1985}-12-18 | -21 | {1985}-12-18 | 12-18 | 12-18 | 12-18 |
| ALBIA | -17 | {1985}-12-18 | -17 | {1985}-12-18 | 12-18 | 12-18 | 12-18 |
| RED ROCK DAM | -14 | {1985}-12-18 | -14 | {1985}-12-18 | 12-18 | 12-18 | 12-18 |
| MANCHESTER | -8 | {1989}-12-18 | -8 | {1989}-12-18 | 12-18 | 12-18 | 12-18 |
| HUMBOLDT 2 | -8 | {1989}-12-18 | -8 | {1989}-12-18 | 12-18 | 12-18 | 12-18 |
| SPENCER NO. 2 | -5 | {1989}-12-18 | -5 | {1989}-12-18 | 12-18 | 12-18 | 12-18 |
| MINEOLA 5 NW | 1 | {1996}-12-18 | 1 | {1996}-12-18 | 12-18 | 12-18 | 12-18 |
| CLIO 4 NW | 3 | {1996}-12-18 | 3 | {1996}-12-18 | 12-18 | 12-18 | 12-18 |
| CHEROKEE # 2 | 1 | {2000,2005}-12-18 | 1 | {2000,2005}-12-18 | 12-18 | 12-18 | 12-18 |
| VILLISCA NO. 2 | 4 | {2000}-12-18 | 4 | {2000}-12-18 | 12-18 | 12-18 | 12-18 |
| WEST UNION 5 NW | 3 | {2000}-12-18 | 3 | {2000}-12-18 | 12-18 | 12-18 | 12-18 |
| KNOXVILLE 3E | 2 | {2000}-12-18 | 2 | {2000}-12-18 | 12-18 | 12-18 | 12-18 |
| GRIMES 4 WSW | 2 | {2000}-12-18 | 2 | {2000}-12-18 | 12-18 | 12-18 | 12-18 |
| RUNNELLS 2SE | 2 | {2000}-12-18 | 2 | {2000}-12-18 | 12-18 | 12-18 | 12-18 |
| PELLA 4 WSW | 2 | {2000}-12-18 | 2 | {2000}-12-18 | 12-18 | 12-18 | 12-18 |
| HORNICK 1 E | 4 | {2005,2008}-12-18 | 4 | {2005,2008}-12-18 | 12-18 | 12-18 | 12-18 |
| WATERLOO #1 | -3 | {2005}-12-18 | -3 | {2005}-12-18 | 12-18 | 12-18 | 12-18 |
| WEST UNION 3SE | -5 | {2005}-12-18 | -5 | {2005}-12-18 | 12-18 | 12-18 | 12-18 |
| MILFORD 3 W | -2 | {2005}-12-18 | -2 | {2005}-12-18 | 12-18 | 12-18 | 12-18 |
| MCGREGOR NO 2 | -5 | {2005}-12-18 | -5 | {2005}-12-18 | 12-18 | 12-18 | 12-18 |
| MAQUOKETA 2 NE | -2 | {2005}-12-18 | -2 | {2005}-12-18 | 12-18 | 12-18 | 12-18 |
| LONE TREE 5 SW | 2 | {2005}-12-18 | 2 | {2005}-12-18 | 12-18 | 12-18 | 12-18 |
| LANSING 4SE | -5 | {2005}-12-18 | -5 | {2005}-12-18 | 12-18 | 12-18 | 12-18 |
| KALONA 1 SSW | 2 | {2005}-12-18 | 2 | {2005}-12-18 | 12-18 | 12-18 | 12-18 |
| IOWA CITY 5 SW | 1 | {2005}-12-18 | 1 | {2005}-12-18 | 12-18 | 12-18 | 12-18 |
| FAIRBANK | -4 | {2005}-12-18 | -4 | {2005}-12-18 | 12-18 | 12-18 | 12-18 |
| DURANGO 3W | -4 | {2005}-12-18 | -4 | {2005}-12-18 | 12-18 | 12-18 | 12-18 |
| CLERMONT | -5 | {2005}-12-18 | -5 | {2005}-12-18 | 12-18 | 12-18 | 12-18 |
| SPENCER | -2 | {2005}-12-18 | -2 | {2005}-12-18 | 12-18 | 12-18 | 12-18 |
| SHELDON 1 N | -1 | {2005}-12-18 | -1 | {2005}-12-18 | 12-18 | 12-18 | 12-18 |
| HANCOCK 7SE | 17 | {2007}-12-18 | 17 | {2007}-12-18 | 12-18 | 12-18 | 12-18 |
| WEST DES MOINES 6 W | 4 | {2008}-12-18 | 4 | {2008}-12-18 | 12-18 | 12-18 | 12-18 |
| DES MOINES (63RD STREET) | 4 | {2008}-12-18 | 4 | {2008}-12-18 | 12-18 | 12-18 | 12-18 |
| DECORAH 2 | 0 | {2008}-12-18 | 0 | {2008}-12-18 | 12-18 | 12-18 | 12-18 |
| WAUKEE 3NE | 7 | {2010}-12-18 | 7 | {2010}-12-18 | 12-18 | 12-18 | 12-18 |
| BRUNSVILLE | 3 | {2010}-12-18 | 3 | {2010}-12-18 | 12-18 | 12-18 | 12-18 |
| AKRON 11E | 3 | {2010}-12-18 | 3 | {2010}-12-18 | 12-18 | 12-18 | 12-18 |
| LAMONI | -1 | {2011,2012}-08-07 | -1 | {2011,2012}-08-07 | 10-26 | 11-11 | 11-21 |
| MASSENA | -15 | {2016,1983}-12-18 | -15 | {2016,1983}-12-18 | 12-18 | 12-18 | 12-18 |
| KANAWHA | -21 | {2016,1983}-12-18 | -21 | {2016,1983}-12-18 | 12-18 | 12-18 | 12-18 |
| CASTANA-EXP-FARM | -18 | {2016,1983}-12-18 | -18 | {2016,1983}-12-18 | 12-18 | 12-18 | 12-18 |
| TRIPOLI 2N | -19 | {2016}-12-18 | -19 | {2016}-12-18 | 12-18 | 12-18 | 12-18 |
| UNDERWOOD | -15 | {2016}-12-18 | -15 | {2016}-12-18 | 12-18 | 12-18 | 12-18 |
| WASHTA | -20 | {2016}-12-18 | -20 | {2016}-12-18 | 12-18 | 12-18 | 12-18 |
| WATERLOO SNOW | -16 | {2016}-12-18 | -16 | {2016}-12-18 | 12-18 | 12-18 | 12-18 |
| OGDEN | -17 | {2016}-12-18 | -17 | {2016}-12-18 | 12-18 | 12-18 | 12-18 |
| OAKLAND MILLS 3 W | -11 | {2016}-12-18 | -11 | {2016}-12-18 | 12-18 | 12-18 | 12-18 |
| NASHUA 2 SW | -20 | {2016}-12-18 | -20 | {2016}-12-18 | 12-18 | 12-18 | 12-18 |
| MOULTON 5 W | -13 | {2016}-12-18 | -13 | {2016}-12-18 | 12-18 | 12-18 | 12-18 |
| MAXWELL | -16 | {2016}-12-18 | -16 | {2016}-12-18 | 12-18 | 12-18 | 12-18 |
| MASON CITY #1 | -22 | {2016}-12-18 | -22 | {2016}-12-18 | 12-18 | 12-18 | 12-18 |
| MARSHALLTOWN 4 SE | -15 | {2016}-12-18 | -15 | {2016}-12-18 | 12-18 | 12-18 | 12-18 |
| MARENGO | -14 | {2016}-12-18 | -14 | {2016}-12-18 | 12-18 | 12-18 | 12-18 |
| LORIMOR | -15 | {2016}-12-18 | -15 | {2016}-12-18 | 12-18 | 12-18 | 12-18 |
| LINN GROVE | -24 | {2016}-12-18 | -24 | {2016}-12-18 | 12-18 | 12-18 | 12-18 |
| LAKE PARK | -26 | {2016}-12-18 | -26 | {2016}-12-18 | 12-18 | 12-18 | 12-18 |
| LAKE MILLS | -23 | {2016}-12-18 | -23 | {2016}-12-18 | 12-18 | 12-18 | 12-18 |
| LADORA | -14 | {2016}-12-18 | -14 | {2016}-12-18 | 12-18 | 12-18 | 12-18 |
| KESLEY | -18 | {2016}-12-18 | -18 | {2016}-12-18 | 12-18 | 12-18 | 12-18 |
| JEFFERSON 2 S | -17 | {2016}-12-18 | -17 | {2016}-12-18 | 12-18 | 12-18 | 12-18 |
| JAMES 1 NE | -21 | {2016}-12-18 | -21 | {2016}-12-18 | 12-18 | 12-18 | 12-18 |
| IOWA CITY 2 | -14 | {2016}-12-18 | -14 | {2016}-12-18 | 12-18 | 12-18 | 12-18 |
| IONIA 2 W | -20 | {2016}-12-18 | -20 | {2016}-12-18 | 12-18 | 12-18 | 12-18 |
| INDIANOLA 5 NNW | -15 | {2016}-12-18 | -15 | {2016}-12-18 | 12-18 | 12-18 | 12-18 |
| HUDSON | -16 | {2016}-12-18 | -16 | {2016}-12-18 | 12-18 | 12-18 | 12-18 |
| Holstein | -21 | {2016}-12-18 | -21 | {2016}-12-18 | 12-18 | 12-18 | 12-18 |
| HORNICK 4 NNE | -20 | {2016}-12-18 | -20 | {2016}-12-18 | 12-18 | 12-18 | 12-18 |
| HAVEN 1 NE | -15 | {2016}-12-18 | -15 | {2016}-12-18 | 12-18 | 12-18 | 12-18 |
| HASTINGS 4NE | -14 | {2016}-12-18 | -14 | {2016}-12-18 | 12-18 | 12-18 | 12-18 |
| HARTWICK 4NW | -14 | {2016}-12-18 | -14 | {2016}-12-18 | 12-18 | 12-18 | 12-18 |
| HAMBURG 2 NE | -13 | {2016}-12-18 | -13 | {2016}-12-18 | 12-18 | 12-18 | 12-18 |
| GRIMES 3 E | -15 | {2016}-12-18 | -15 | {2016}-12-18 | 12-18 | 12-18 | 12-18 |
| GLENWOOD | -11 | {2016}-12-18 | -11 | {2016}-12-18 | 12-18 | 12-18 | 12-18 |
| GARBER | -16 | {2016}-12-18 | -16 | {2016}-12-18 | 12-18 | 12-18 | 12-18 |
| FULTON | -15 | {2016}-12-18 | -15 | {2016}-12-18 | 12-18 | 12-18 | 12-18 |
| FORT DODGE 4 NW | -19 | {2016}-12-18 | -19 | {2016}-12-18 | 12-18 | 12-18 | 12-18 |
| EVERLY 3 WNW | -24 | {2016}-12-18 | -24 | {2016}-12-18 | 12-18 | 12-18 | 12-18 |
| ESTHERVILLE 1WSW | -26 | {2016}-12-18 | -26 | {2016}-12-18 | 12-18 | 12-18 | 12-18 |
| EMMETSBURG 2 NW | -25 | {2016}-12-18 | -25 | {2016}-12-18 | 12-18 | 12-18 | 12-18 |
| ELMA | -20 | {2016}-12-18 | -20 | {2016}-12-18 | 12-18 | 12-18 | 12-18 |
| ELKADER 1 SE | -17 | {2016}-12-18 | -17 | {2016}-12-18 | 12-18 | 12-18 | 12-18 |
| ELBERON 3 S | -15 | {2016}-12-18 | -15 | {2016}-12-18 | 12-18 | 12-18 | 12-18 |
| EDDYVILLE NO 2 | -14 | {2016}-12-18 | -14 | {2016}-12-18 | 12-18 | 12-18 | 12-18 |
| DUBUQUE #3 | -11 | {2016}-12-18 | -11 | {2016}-12-18 | 12-18 | 12-18 | 12-18 |
| DUBUQUE NO 2 | -15 | {2016}-12-18 | -15 | {2016}-12-18 | 12-18 | 12-18 | 12-18 |
| DORCHESTER HWY 76 | -19 | {2016}-12-18 | -19 | {2016}-12-18 | 12-18 | 12-18 | 12-18 |
| DE WITT 4 S | -10 | {2016}-12-18 | -10 | {2016}-12-18 | 12-18 | 12-18 | 12-18 |
| DES MOINES SNOW | -15 | {2016}-12-18 | -15 | {2016}-12-18 | 12-18 | 12-18 | 12-18 |
| DALLAS 2 NW | -14 | {2016}-12-18 | -14 | {2016}-12-18 | 12-18 | 12-18 | 12-18 |
| Dakota City | -19 | {2016}-12-18 | -19 | {2016}-12-18 | 12-18 | 12-18 | 12-18 |
| CORALVILLE | -14 | {2016}-12-18 | -14 | {2016}-12-18 | 12-18 | 12-18 | 12-18 |
| CONESVILLE 3 NE | -13 | {2016}-12-18 | -13 | {2016}-12-18 | 12-18 | 12-18 | 12-18 |
| COLUMBIA | -14 | {2016}-12-18 | -14 | {2016}-12-18 | 12-18 | 12-18 | 12-18 |
| COGGON | -15 | {2016}-12-18 | -15 | {2016}-12-18 | 12-18 | 12-18 | 12-18 |
| CLARINDA 1 E | -14 | {2016}-12-18 | -14 | {2016}-12-18 | 12-18 | 12-18 | 12-18 |
| CHARLES CITY NO 2 | -21 | {2016}-12-18 | -21 | {2016}-12-18 | 12-18 | 12-18 | 12-18 |
| CENTRAL CITY | -15 | {2016}-12-18 | -15 | {2016}-12-18 | 12-18 | 12-18 | 12-18 |
| CALMAR NE | -19 | {2016}-12-18 | -19 | {2016}-12-18 | 12-18 | 12-18 | 12-18 |
| BUSSEY 3 WNW | -14 | {2016}-12-18 | -14 | {2016}-12-18 | 12-18 | 12-18 | 12-18 |
| ORANGE CITY | -24 | {2016}-12-18 | -24 | {2016}-12-18 | 12-18 | 12-18 | 12-18 |
| BRITT | -22 | {2016}-12-18 | -22 | {2016}-12-18 | 12-18 | 12-18 | 12-18 |
| BLOCKTON 1W | -14 | {2016}-12-18 | -14 | {2016}-12-18 | 12-18 | 12-18 | 12-18 |
| BELLE PLAINE 3 S | -14 | {2016}-12-18 | -14 | {2016}-12-18 | 12-18 | 12-18 | 12-18 |
| BAYARD 6 SE | -16 | {2016}-12-18 | -16 | {2016}-12-18 | 12-18 | 12-18 | 12-18 |
| ANKENY 2 SE | -15 | {2016}-12-18 | -15 | {2016}-12-18 | 12-18 | 12-18 | 12-18 |
| ANAMOSA NO 2 | -15 | {2016}-12-18 | -15 | {2016}-12-18 | 12-18 | 12-18 | 12-18 |
| AMES 3 N | -15 | {2016}-12-18 | -15 | {2016}-12-18 | 12-18 | 12-18 | 12-18 |
| ALTOONA 4W | -15 | {2016}-12-18 | -15 | {2016}-12-18 | 12-18 | 12-18 | 12-18 |
| ALTON | -24 | {2016}-12-18 | -24 | {2016}-12-18 | 12-18 | 12-18 | 12-18 |
| ALGONA 1NNW | -23 | {2016}-12-18 | -23 | {2016}-12-18 | 12-18 | 12-18 | 12-18 |
| AKRON | -23 | {2016}-12-18 | -23 | {2016}-12-18 | 12-18 | 12-18 | 12-18 |
| SWISHER #2 | -13 | {2016}-12-18 | -13 | {2016}-12-18 | 12-18 | 12-18 | 12-18 |
| STORY CITY | -17 | {2016}-12-18 | -17 | {2016}-12-18 | 12-18 | 12-18 | 12-18 |
| SIOUX CITY HWY 77 BRG | -22 | {2016}-12-18 | -22 | {2016}-12-18 | 12-18 | 12-18 | 12-18 |
| SIGOURNEY 2 S | -13 | {2016}-12-18 | -13 | {2016}-12-18 | 12-18 | 12-18 | 12-18 |
| Sheldon | -26 | {2016}-12-18 | -26 | {2016}-12-18 | 12-18 | 12-18 | 12-18 |
| SAYLORVILLE 3WNW | -15 | {2016}-12-18 | -15 | {2016}-12-18 | 12-18 | 12-18 | 12-18 |
| SALEM 1 S | -9 | {2016}-12-18 | -9 | {2016}-12-18 | 12-18 | 12-18 | 12-18 |
| ROCKWELL CITY NO. 2 | -19 | {2016}-12-18 | -19 | {2016}-12-18 | 12-18 | 12-18 | 12-18 |
| ROCK VALLEY | -25 | {2016}-12-18 | -25 | {2016}-12-18 | 12-18 | 12-18 | 12-18 |
| RINGSTED | -24 | {2016}-12-18 | -24 | {2016}-12-18 | 12-18 | 12-18 | 12-18 |
| REMSEN NO. 2 | -23 | {2016}-12-18 | -23 | {2016}-12-18 | 12-18 | 12-18 | 12-18 |
| RANDOLPH 1 W | -13 | {2016}-12-18 | -13 | {2016}-12-18 | 12-18 | 12-18 | 12-18 |
| PETERSON | -24 | {2016}-12-18 | -24 | {2016}-12-18 | 12-18 | 12-18 | 12-18 |
| OXFORD JUNCTION 1 S | -14 | {2016}-12-18 | -14 | {2016}-12-18 | 12-18 | 12-18 | 12-18 |
| PANORA | -16 | {2016}-12-18 | -16 | {2016}-12-18 | 12-18 | 12-18 | 12-18 |
| OTTUMWA | -13 | {2016}-12-18 | -13 | {2016}-12-18 | 12-18 | 12-18 | 12-18 |
| OSKALOOSA 4 N | -14 | {2016}-12-18 | -14 | {2016}-12-18 | 12-18 | 12-18 | 12-18 |
| WAUKON 4SW | 15 | {2018}-12-18 | 15 | {2018}-12-18 | 12-18 | 12-18 | 12-18 |