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:
BATTLE CREEK 3NE 32 {2014}-09-13 24 {2012}-09-23 10-04 10-15 10-31
SIBLEY-5-NNE 30 {1950}-08-20 23 -09-11 10-07 10-26 11-03
ROCK-RAPIDS 31 {1974}-09-03 26 {1894}-09-10 10-07 10-24 11-05
Estherville 4E 32 {1924}-09-09 27 {1929}-09-18 10-07 10-27 11-06
CHEROKEE 31 {1974}-09-03 27 -09-11 10-07 10-27 11-07
SANBORN 32 {1974}-09-03 25 {1929}-09-18 10-10 10-27 11-07
SIOUX-RAPIDS 31 {1974}-09-03 28 {1991}-09-19 10-09 10-27 11-07
ESTHERVILLE MUNICIPAL AP 31 {2014}-09-13 28 {2007}-09-15 10-10 10-24 11-07
MASON CITY MUNICIPAL AP 31 {2014}-09-13 26 {2011}-09-15 10-09 10-28 11-07
Milford 32 {1974}-09-03 28 {1929}-09-18 10-13 10-31 11-08
Spencer 31 {1974}-09-03 28 {2007}-09-15 10-09 10-27 11-08
Iowa - Northwest Climate Division 32 {1974}-09-03 26 {1918}-09-20 10-12 10-28 11-08
Iowa Drought Region 1 - Northwest 32 {1974}-09-03 28 {1991}-09-19 10-12 10-28 11-08
Spencer Area 31 {1974}-09-03 28 {2007}-09-15 10-09 10-27 11-08
LEMARS 31 -09-11 28 {1902}-09-12 10-12 10-28 11-08
MAPLETON NO. 2 31 -09-11 27 {1991}-09-19 10-15 11-02 11-08
LAKE PARK 30 {1940}-09-12 28 {1916}-09-15 10-12 10-28 11-08
MASON-CITY 30 {1915}-08-30 28 {1923}-09-14 10-10 10-28 11-09
FOREST-CITY 31 {1949}-09-01 27 {1929}-09-18 10-13 10-28 11-09
Elkader 6SSW (Osborn) 32 {1893}-08-29 0 {2002}-09-02 10-09 10-27 11-10
IOWA-FALLS 31 {1915}-08-30 28 {1894}-09-18 10-12 11-01 11-10
NEW-HAMPTON 28 {1949}-09-01 28 {1949}-09-01 10-13 11-01 11-10
FAYETTE 32 {1949}-09-01 27 {1902}-09-12 10-10 10-28 11-10
POCAHONTAS 31 {1946}-09-02 27 {1929}-09-18 10-10 10-28 11-10
ALGONA 29 {1893}-09-02 27 {1929}-09-18 10-17 11-01 11-10
ATLANTIC-1-NE 30 {1893}-09-02 28 {1902,1955}-09-12 10-17 11-01 11-10
CARROLL-2-SSW 28 {1974}-09-03 28 {1974}-09-03 10-16 11-01 11-10
SIOUX CENTER 2 SE 31 {1974}-09-03 24 {1991}-09-19 10-16 10-28 11-10
SWEA CITY 4 W 32 {1974}-09-03 26 {1974}-09-22 10-09 10-29 11-10
Ida Grove Area 32 {1974}-09-03 27 {1918}-09-20 10-16 10-31 11-10
HAMPTON-2-NW 32 -09-11 28 {1955}-09-12 10-13 11-01 11-10
WEBSTER-CITY 30 -09-11 25 {1929}-09-18 10-12 10-28 11-10
PRIMGHAR 30 {1902}-09-12 25 {1901}-09-18 10-16 10-31 11-10
ROCKWELL-CITY 32 {1902}-09-12 28 {1929}-09-18 10-17 11-01 11-10
SPIRIT LAKE 31 {1902}-09-12 28 {1929}-09-18 10-17 11-01 11-10
STORM-LAKE-2-E 32 {1902}-09-12 28 {1929}-09-18 10-17 11-02 11-10
AUDUBON 30 {1902,1955}-09-12 27 {1896}-09-19 10-17 11-01 11-10
Emmetsburg 32 {1902}-09-12 28 {1929}-09-18 10-13 11-01 11-10
SIOUX-CITY-WSO-AP 30 {1902}-09-13 25 {1995}-09-22 10-17 11-02 11-10
Iowa - North Central Climate Division 32 {1902}-09-13 28 {1929}-09-18 10-12 11-01 11-10
Spencer Airport 32 {2014}-09-13 28 {2007}-09-15 10-04 10-24 11-10
Sioux City Area 30 {1902}-09-13 25 {1995}-09-22 10-17 11-02 11-10
OSAGE 30 {1949}-09-14 28 {1929}-09-18 10-13 11-01 11-10
ROCK VALLEY 32 {2007,2011}-09-15 28 {1995}-09-22 10-12 10-31 11-10
SIOUX CITY ANG 31 {2012}-09-23 20 {2004}-10-02 10-12 10-26 11-10
HOLSTEIN 5 NNW 30 {2020}-10-02 28 {2019}-10-12 10-12 10-25 11-10
JEFFERSON 32 {1893}-08-29 28 {1929}-09-18 10-17 11-02 11-11
ALLISON 32 {1915}-08-30 28 {1926}-09-25 10-17 11-02 11-11
DECORAH-2-N 32 {1915}-08-30 28 {1946}-09-02 10-10 11-01 11-11
Postville 32 {1919}-09-02 20 {1918}-09-21 10-17 11-02 11-11
GUTHRIE-CENTER 31 {1893}-09-02 28 {1991}-09-19 10-17 11-02 11-11
FORT-DODGE 32 {1974}-09-03 27 {1902}-09-13 10-17 11-02 11-11
OAKLAND-2-E 32 {1974}-09-03 28 {1995}-09-22 10-17 11-03 11-11
SAC-CITY 32 {1974}-09-03 28 {1918}-09-20 10-16 11-01 11-11
Oelwein Area 20 {1942}-09-05 20 {1942}-09-05 10-16 11-02 11-11
GRINNELL-3-SW 31 {1976}-09-10 27 {1991}-09-20 10-17 11-02 11-11
CASCADE 32 -09-11 28 {1953,1974}-09-22 10-10 11-03 11-11
TOLEDO 31 -09-11 27 {1896}-09-20 10-17 11-02 11-11
WATERLOO 32 -09-11 28 {1929}-09-18 10-13 11-02 11-11
Waterloo Area 32 -09-11 28 {1929}-09-18 10-13 11-02 11-11
GRUNDY-CENTER 32 {1902}-09-12 28 {1929}-09-18 10-13 11-02 11-11
LOGAN 30 {1902}-09-12 28 {1902}-09-13 10-17 11-02 11-11
MARSHALLTOWN 31 {1955}-09-12 28 {1896}-09-20 10-13 11-02 11-11
PERRY 32 {1955}-09-12 27 {1929}-09-18 10-17 11-02 11-11
Iowa Drought Region 2 - Northcentral 32 {1902}-09-12 27 {1913}-09-22 10-17 11-01 11-11
Iowa - West Central Climate Division 31 {1902}-09-12 28 {1918}-09-20 10-17 11-02 11-11
Boone 32 {1975}-09-12 27 {1929}-09-18 10-17 11-02 11-11
CHARLES-CITY 32 {1902,1955}-09-12 28 {1991}-09-20 10-16 11-02 11-11
DENISON 29 {1902}-09-12 21 {1918}-09-21 10-18 11-02 11-11
Iowa Average 32 {1902}-09-13 24 {1942}-09-28 10-17 11-02 11-11
LOWDEN 32 {2014}-09-13 26 {2012}-09-24 10-13 11-01 11-11
MANCHESTER-2 32 {2014}-09-13 27 {1984}-09-16 10-13 11-02 11-11
STANLEY 31 {2014}-09-13 26 {2012}-09-23 10-11 10-26 11-11
Iowa - Northeast Climate Division 32 {1902}-09-13 28 {1974}-09-22 10-13 11-02 11-11
Ames Area 31 {1902}-09-13 26 {1918}-09-21 10-17 11-02 11-11
LITTLE SIOUX 2NW 31 {2007}-09-15 27 {2012}-09-23 10-08 10-25 11-11
MARSHALLTOWN MUNICIPAL AP 30 {2007}-09-15 27 {2012}-09-23 10-14 10-31 11-11
OELWEIN 1E 32 {2011}-09-15 28 {2012}-10-05 10-13 10-29 11-11
OGDEN 32 {2007}-09-15 26 {2003}-10-02 10-14 11-07 11-11
Iowa - Central Climate Division 32 {2007}-09-15 28 {1913}-09-22 10-17 11-02 11-11
AMES MUNICIPAL AP 31 {2007}-09-15 27 {2003}-09-30 10-13 10-31 11-11
DAVENPORT WFO 30 {2012}-09-23 27 {2012}-10-05 10-15 10-29 11-11
BELLE-PLAINE 31 -09-11 28 {1916,1929}-09-18 10-17 11-03 11-12
MAQUOKETA-2-W 31 -09-11 28 {1983}-09-23 10-17 11-03 11-12
WILLIAMSBURG 32 -09-11 28 {1991}-09-20 10-18 11-03 11-12
VINTON 32 {1902,1953}-09-13 28 {1982}-09-21 10-17 11-03 11-12
Iowa Drought Region 3 - Northeast 32 {1902}-09-13 27 {1926}-09-26 10-17 11-03 11-12
AMES-8-WSW 31 {1902}-09-13 26 {1918}-09-21 10-18 11-03 11-12
Cedar Rapids Airport 31 {2007}-09-15 28 {2012}-09-24 10-17 11-05 11-12
Dubuque Airport 32 {2007}-09-15 28 {1956}-09-20 10-17 11-03 11-12
DES MOINES WSFO-JOHNSTON 31 {1999}-09-21 28 {2004}-10-02 10-21 11-10 11-12
ANAMOSA 3 SSW 30 {2012}-09-24 26 {2015}-10-17 10-13 10-29 11-12
Iowa Drought Region 4 - Southwest 32 {1902}-09-12 26 {1942}-09-28 10-19 11-03 11-13
CORNING 32 {1902}-09-12 27 {1983}-09-21 10-17 11-03 11-13
Creston 31 {1924}-09-15 28 {1991}-09-19 10-18 11-03 11-13
MOUNT-AYR 32 {1902}-09-13 28 {1991}-09-19 10-19 11-05 11-19
Iowa - Southwest Climate Division 32 {1902}-09-13 26 {1942}-09-28 10-19 11-05 11-19
CLARINDA 31 {1902}-09-13 28 {1918}-09-21 10-19 11-03 11-19
Cedar Rapids Area 31 {2007}-09-15 28 {2012}-09-24 10-18 11-03 11-19
AMES 5 SE 32 {1902}-09-13 28 {1926}-09-26 10-19 11-04 11-20
BEACONSFIELD 27 {1991}-09-19 27 {1991}-09-19 10-19 11-05 11-20
LAMONI 29 {2004}-10-02 27 {2012}-10-06 10-24 11-10 11-20
BELLEVUE-L-AND-D-12 32 {1986}-08-30 28 {1974,1995}-09-23 10-17 11-06 11-21
RED-OAK 32 -09-11 28 {1995}-09-22 10-19 11-03 11-21
WINTERSET 31 {1955}-09-12 26 {1896}-09-20 10-19 11-07 11-21
CHARITON 32 {1955}-09-12 28 {1918,1991}-09-20 10-17 11-05 11-21
OSKALOOSA 31 {1902}-09-13 27 {1991}-09-20 10-19 11-08 11-21
SIGOURNEY 32 {1902}-09-13 25 {1913}-09-21 10-19 11-08 11-21
WASHINGTON 30 {1902}-09-13 28 {1983}-09-23 10-19 11-08 11-21
Iowa City 32 {1923}-09-14 28 {1916}-09-18 10-19 11-06 11-21
CEDAR-RAPIDS-1 32 {2007}-09-15 24 {1926}-09-26 10-20 11-06 11-21
OSCEOLA-3-WSW 31 {2007}-09-15 28 {1974}-09-22 10-19 11-07 11-21
Dubuque Area 32 {2007}-09-15 28 {1956}-09-20 10-19 11-05 11-21
SHENANDOAH-1-NE 32 {1937}-09-16 28 {1918}-09-20 10-19 11-07 11-21
GREENFIELD 32 {1981}-09-17 27 {1913}-09-22 10-19 11-08 11-21
NEWTON 32 {1929}-09-18 23 {1942}-09-28 10-20 11-06 11-21
Iowa - East Central Climate Division 32 {1929}-09-18 28 {1926}-09-26 10-18 11-05 11-21
GUTTENBERG-L-AND-D-10 32 {1973}-09-18 25 {1942}-09-28 10-19 11-07 11-21
KNOXVILLE 31 {1916}-09-18 28 {1926}-09-26 10-24 11-08 11-21
Lamoni 32 {1901}-09-18 27 {1942}-09-28 10-24 11-08 11-21
Iowa - South Central Climate Division 32 {1991}-09-19 25 {1942}-09-28 10-19 11-08 11-21
Allerton 31 {1991}-09-19 27 {1913}-09-22 10-19 11-08 11-21
Iowa Drought Region 5 - Southeast 32 {1991}-09-20 24 {1942}-09-28 10-19 11-08 11-21
MUSCATINE 29 {1991}-09-20 23 {1942}-09-28 10-24 11-10 11-21
IOWA CITY MUNICIPAL AP 32 {1991}-09-20 26 {1995}-09-23 10-19 11-07 11-21
Des Moines Area 31 {1995}-09-22 26 {1942}-09-28 10-24 11-08 11-21
RATHBUN DAM 32 {1974}-09-22 28 {1985}-10-01 10-18 11-08 11-21
Des Moines Airport 31 {1995}-09-22 26 {1942}-09-28 10-24 11-08 11-21
FAIRFIELD 32 -09-11 28 {1918}-09-21 10-24 11-08 11-22
KEOSAUQUA 31 -09-11 28 {1916}-09-18 10-24 11-09 11-22
COLUMBUS JUNCT 2 SSW 31 {1955}-09-12 28 {1991}-09-20 10-24 11-08 11-22
MOUNT-PLEASANT 32 {1902}-09-13 28 {1942}-09-24 10-25 11-10 11-22
CLINTON-1 31 {1902}-09-13 28 {1928}-09-25 10-20 11-09 11-22
CENTERVILLE 31 {1913}-09-13 28 {1913}-09-22 10-25 11-10 11-22
Ottumwa 32 {2007}-09-15 23 {1942}-09-28 10-24 11-09 11-22
Iowa - Southeast Climate Division 32 {1896}-09-20 25 {1942}-09-28 10-24 11-08 11-22
DUBUQUE-LOCK-AND-DAM 31 {1956}-09-20 24 {1899}-09-30 10-25 11-10 11-22
Donnellson 31 {1991}-09-20 25 {1942}-09-28 10-19 11-10 11-22
MUSCATINE 2N 27 {2003}-10-02 27 {2003}-10-02 10-17 11-11 11-22
Le Claire L&D 14 32 {1942}-09-26 28 {1942}-09-28 10-28 11-11 11-23
Burlington Airport 30 {1918}-09-18 25 {1942}-09-28 10-27 11-10 11-24
Fort Madison 32 {1913}-09-22 26 {1942}-09-28 10-27 11-11 11-24
BURLINGTON 32 {1984}-09-26 28 {1974}-10-02 10-27 11-11 11-27
NORTHWOOD -10 {1929}-11-29 -10 {1929}-11-29 11-29 11-29 11-29