Iowa Environmental Mesonet

Iowa State University Department of Agronomy

Climodat reports are a great source of Iowa climate data

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:
ALGONA 29 1893-09-02 27 1929-09-18 10-17 11-02 11-10
GUTHRIE-CENTER 31 1893-09-02 28 1991-09-19 10-17 11-02 11-11
LEMARS 25 1893-09-02 25 1893-09-02 10-17 10-29 11-08
ATLANTIC-1-NE 30 1893-09-02 28 1902-09-12 10-17 11-02 11-10
GLENWOOD 27 1901-09-18 27 1901-09-18 10-19 11-04 11-21
CORNING 32 1902-09-12 27 1983-09-21 10-18 11-03 11-19
ROCKWELL-CITY 32 1902-09-12 28 1929-09-18 10-17 11-02 11-10
LOGAN 30 1902-09-12 28 1902-09-13 10-18 11-02 11-12
DENISON 29 1902-09-12 21 1918-09-21 10-18 11-02 11-12
STORM-LAKE-2-E 32 1902-09-12 28 1929-09-18 10-17 11-02 11-08
CLARINDA 31 1902-09-13 28 1918-09-21 10-19 11-03 11-19
WASHINGTON 30 1902-09-13 28 1983-09-23 10-24 11-08 11-22
OSKALOOSA 31 1902-09-13 27 1991-09-20 10-19 11-05 11-21
TIPTON 32 1902-09-13 28 1991-09-20 10-19 11-05 11-21
AMES-8-WSW 31 1902-09-13 26 1918-09-21 10-18 11-02 11-12
Iowa Average 31 1902-09-13 27 1926-09-26 10-19 11-03 11-19
MOUNT-AYR 32 1902-09-13 28 1991-09-19 10-23 11-05 11-21
MASON-CITY 30 1915-08-30 28 1923-09-14 10-10 11-01 11-08
DECORAH-2-N 32 1915-08-30 28 1946-09-02 10-10 11-02 11-10
KEOSAUQUA 31 1917-09-11 28 1916-09-18 10-24 11-09 11-22
MAQUOKETA-2-W 31 1917-09-11 28 1983-09-23 10-17 11-04 11-13
FAIRFIELD 32 1917-09-11 28 1918-09-21 10-24 11-08 11-22
WATERLOO 32 1917-09-11 28 1929-09-18 10-13 11-02 11-10
CLINTON-1 22 1924-08-31 22 1924-08-31 10-19 11-06 11-22
FAYETTE 32 1949-09-01 27 1902-09-12 10-10 10-28 11-10
NEW-HAMPTON 28 1949-09-01 28 1949-09-01 10-17 11-02 11-10
VINTON 32 1953-09-13 28 1982-09-21 10-10 11-03 11-20
NORTHWOOD 31 1953-09-13 26 1974-09-22 10-09 11-02 11-05
ONAWA 30 1955-09-11 28 1991-09-19 10-19 11-02 11-11
HAMPTON-2-NW 32 1955-09-11 28 1955-09-12 10-17 11-02 11-10
OELWEIN-2-S 28 1955-09-11 28 1955-09-11 10-10 11-02 11-10
CASCADE 32 1955-09-11 28 1953-09-22 10-07 11-03 11-10
WEBSTER-CITY 30 1955-09-11 25 1929-09-18 10-13 11-02 11-10
AUDUBON 30 1955-09-12 28 1991-09-20 10-10 11-02 11-10
WINTERSET 31 1955-09-12 28 1962-09-20 10-18 11-04 11-10
CHARITON 32 1955-09-12 28 1991-09-20 10-18 11-04 11-20
BELLE-PLAINE 32 1955-09-12 28 1991-09-20 10-18 11-04 11-19
PERRY 32 1955-09-12 28 1974-09-22 10-09 11-03 11-10
WILLIAMSBURG 31 1955-09-12 28 1991-09-20 10-18 11-04 11-20
CHARLES-CITY 32 1955-09-12 28 1991-09-20 10-10 11-03 11-10
MARSHALLTOWN 31 1955-09-12 28 1896-09-20 10-17 11-02 11-11
ANAMOSA-1-WNW 29 1955-09-12 27 1956-09-20 10-10 11-03 11-12
WAUKON 32 1956-09-20 27 1984-09-26 10-10 11-02 11-09
IOWA-CITY 32 1956-09-20 24 1958-10-01 10-19 11-06 11-21
DUBUQUE-LOCK-AND-DAM 31 1956-09-20 24 1899-09-30 10-25 11-10 11-22
Eldora 32 1962-09-20 28 1974-09-22 10-10 11-03 11-10
GUTTENBERG-L-AND-D-10 32 1973-09-18 28 1984-09-29 10-19 11-05 11-21
ROCK-RAPIDS 31 1974-09-03 26 1894-09-10 10-06 10-24 11-03
CHEROKEE 31 1974-09-03 27 1955-09-11 10-07 10-26 11-04
Sheldon 32 1974-09-03 28 2007-09-15 10-09 10-28 11-04
OAKLAND-2-E 32 1974-09-03 28 1995-09-22 10-10 11-03 11-10
CLARION 32 1974-09-03 25 1974-09-22 10-09 10-28 11-07
SAC-CITY 32 1974-09-03 27 1974-09-22 10-10 11-02 11-11
CARROLL-2-SSW 28 1974-09-03 28 1974-09-03 10-07 10-29 11-08
SIOUX-RAPIDS 31 1974-09-03 28 1991-09-19 10-09 10-29 11-06
FORT-DODGE 32 1974-09-03 28 1995-09-22 10-09 11-02 11-10
HAWARDEN 31 1974-09-03 24 1991-09-19 10-09 10-28 11-04
SIBLEY-5-NNE 30 1974-09-03 23 1955-09-11 10-04 10-26 11-03
INDEPENDENCE-2-W 32 1974-09-03 28 1975-09-13 10-10 11-03 11-10
NEWTON 29 1974-09-22 27 1972-09-30 10-18 11-05 11-21
Boone 32 1975-09-12 28 1981-09-18 10-10 11-01 11-04
CRESCO-1-NE 31 1975-09-13 27 1991-09-20 10-07 10-29 11-05
GRINNELL-3-SW 31 1976-09-10 27 1991-09-20 10-17 11-03 11-12
IOWA-FALLS 32 1976-09-10 26 1974-09-22 10-10 11-02 11-07
HUMBOLDT-2 32 1976-09-17 26 1974-09-22 10-09 11-02 11-07
INDIANOLA-2-SSW 30 1979-09-15 28 1979-09-22 10-19 11-08 11-21
SHENANDOAH-1-NE 30 1980-09-17 26 1983-09-23 10-19 11-05 11-20
Ottumwa 29 1981-08-03 27 1984-09-29 10-24 11-08 11-24
GREENFIELD 32 1981-09-17 28 1995-09-22 10-19 11-04 11-20
FORT-MADISON 32 1983-09-23 27 1974-10-02 10-28 11-10 11-24
PRIMGHAR 31 1984-09-15 27 1991-09-19 10-09 11-02 11-08
Le Claire L&D 14 32 1984-09-29 25 1974-10-02 10-28 11-11 11-24
ALBIA 31 1991-09-19 25 1984-09-29 10-25 11-06 11-21
BEDFORD-1-NNW 27 1991-09-19 27 1991-09-19 10-19 11-04 11-20
Lamoni 32 1991-09-19 24 1974-10-02 10-19 11-05 11-21
KNOXVILLE 31 1991-09-19 27 1974-10-02 10-19 11-07 11-21
EMMETSBURG 31 1991-09-19 24 1995-09-22 10-10 11-02 11-08
CENTERVILLE 32 1991-09-19 27 1979-10-05 10-19 11-05 11-23
CASTANA-EXP-FARM 30 1991-09-19 28 1995-09-22 10-18 11-03 11-19
SIDNEY 30 1991-09-19 28 1995-09-22 10-27 11-05 11-24
Creston 28 1991-09-19 28 1991-09-19 10-18 11-03 11-20
HARLAN 29 1991-09-19 27 1951-09-28 10-17 11-03 11-10
MOUNT-PLEASANT 29 1991-09-20 25 1974-10-02 10-19 11-10 11-21
MUSCATINE 29 1991-09-20 26 1984-09-29 10-19 11-10 11-24
ALLISON 30 1991-09-20 28 1984-09-26 10-18 11-03 11-16
BELLEVUE-L-AND-D-12 31 1991-09-20 25 1995-09-23 10-18 11-04 11-21
BLOOMFIELD 31 1991-09-20 25 1974-10-02 10-19 11-05 11-21
ANKENY-3-S 32 1991-09-20 28 1984-09-26 10-18 11-04 11-20
Burlington 32 1991-09-20 26 2003-10-02 10-27 11-10 11-24
RED-OAK 32 1993-09-15 28 1995-09-22 10-18 11-04 11-20
SIGOURNEY 31 1995-09-22 28 1964-09-28 10-19 11-05 11-21
Des Moines Airport 31 1995-09-22 28 1984-09-29 10-19 11-05 11-20
ESTHERVILLE-2-N 30 2007-09-15 28 1991-09-20 10-07 10-28 11-05
FOREST-CITY 31 2007-09-15 26 1974-09-22 10-09 11-02 11-08
SIOUX-CITY-WSO-AP 32 2007-09-15 25 1995-09-22 10-15 11-02 11-08
GRUNDY-CENTER 31 2007-09-15 27 1974-09-22 10-07 10-29 11-07
TRIPOLI-4-N 31 2007-09-15 27 1974-09-22 10-10 11-03 11-10
MANCHESTER-2 29 2007-09-15 27 1984-09-16 10-07 10-28 11-09
POCAHONTAS 30 2007-09-15 28 1983-09-20 10-07 10-28 11-05
BRITT 31 2007-09-15 25 1983-09-22 10-09 11-02 11-08
OSCEOLA-3-WSW 31 2007-09-15 28 1974-09-22 10-18 11-04 11-20
OSAGE 32 2007-09-15 28 1974-09-22 10-17 11-03 11-10
TOLEDO 31 2007-09-15 28 1962-09-20 10-10 11-03 11-10
CEDAR-RAPIDS-1 32 2007-09-15 24 1926-09-26 10-19 11-05 11-21
JEFFERSON 32 2007-09-16 23 1974-10-02 10-18 11-04 11-19