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:
Elkader 6SSW (Osborn) 32 {1893}-08-29 0 {2002}-09-02 10-09 10-28 11-10
JEFFERSON 32 {1893}-08-29 28 {1929}-09-18 10-17 11-02 11-11
ATLANTIC-1-NE 30 {1893}-09-02 28 {1902,1955}-09-12 10-16 11-01 11-10
ALGONA 29 {1893}-09-02 27 {1929}-09-18 10-17 11-01 11-10
Iowa - Southeast Climate Division 32 {1896}-09-20 25 {1942}-09-28 10-25 11-09 11-22
Lamoni 32 {1901}-09-18 27 {1942}-09-28 10-24 11-08 11-21
VINTON 32 {1902,1953}-09-13 28 {1982}-09-21 10-17 11-03 11-12
AUDUBON 30 {1902,1955}-09-12 27 {1896}-09-19 10-17 11-01 11-10
CHARLES-CITY 32 {1902,1955}-09-12 28 {1991}-09-20 10-16 11-02 11-11
Iowa - North Central Climate Division 32 {1902,2014}-09-13 28 {1929}-09-18 10-17 11-02 11-10
Iowa - West Central Climate Division 31 {1902}-09-12 28 {1918}-09-20 10-17 11-02 11-11
Iowa - Northwest Climate Division 30 {1902}-09-12 26 {1918}-09-20 10-13 10-31 11-10
CORNING 32 {1902}-09-12 27 {1983}-09-21 10-17 11-03 11-13
SPIRIT LAKE 31 {1902}-09-12 28 {1929}-09-18 10-17 11-01 11-10
Iowa Drought Region 4 - Southwest 32 {1902}-09-12 26 {1942}-09-28 10-19 11-05 11-19
LOGAN 30 {1902}-09-12 28 {1902}-09-13 10-17 11-02 11-11
PRIMGHAR 30 {1902}-09-12 25 {1901}-09-18 10-16 10-31 11-10
GUTHRIE-CENTER 31 {1902}-09-12 28 {1991}-09-19 10-17 11-02 11-11
Iowa Drought Region 2 - Northcentral 32 {1902}-09-12 27 {1913}-09-22 10-17 11-02 11-11
STORM-LAKE-2-E 32 {1902}-09-12 28 {1929}-09-18 10-17 11-01 11-10
Iowa Drought Region 1 - Northwest 30 {1902}-09-12 25 {1918}-09-20 10-17 11-01 11-10
DENISON 29 {1902}-09-12 21 {1918}-09-21 10-18 11-02 11-11
GRUNDY-CENTER 32 {1902}-09-12 28 {1929}-09-18 10-13 11-02 11-11
SIOUX-CITY-WSO-AP 30 {1902}-09-13 25 {1995}-09-22 10-17 11-02 11-10
Sioux City Area 30 {1902}-09-13 25 {1995}-09-22 10-17 11-02 11-10
MOUNT-PLEASANT 32 {1902}-09-13 28 {1942}-09-24 10-25 11-10 11-22
Ames Area 31 {1902}-09-13 26 {1918}-09-21 10-17 11-02 11-11
Iowa Drought Region 3 - Northeast 32 {1902}-09-13 27 {1926}-09-26 10-19 11-03 11-12
AMES 5 SE 32 {1902}-09-13 28 {1926}-09-26 10-19 11-04 11-20
Iowa - Northeast Climate Division 32 {1902}-09-13 26 {1926}-09-26 10-17 11-02 11-11
AMES-8-WSW 31 {1902}-09-13 26 {1918}-09-21 10-18 11-02 11-12
MOUNT-AYR 32 {1902}-09-13 28 {1991}-09-19 10-19 11-05 11-19
WASHINGTON 30 {1902}-09-13 28 {1983}-09-23 10-24 11-08 11-21
OSKALOOSA 31 {1902}-09-13 27 {1991}-09-20 10-19 11-08 11-21
CLARINDA 31 {1902}-09-13 28 {1918}-09-21 10-18 11-02 11-19
Iowa Average 32 {1902}-09-13 24 {1942}-09-28 10-19 11-03 11-11
SIGOURNEY 32 {1902}-09-13 25 {1913}-09-21 10-19 11-08 11-22
Iowa - Southwest Climate Division 32 {1902}-09-13 26 {1942}-09-28 10-24 11-08 11-21
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
Fort Madison 32 {1913}-09-22 26 {1942}-09-28 10-27 11-11 11-24
IOWA-FALLS 31 {1915}-08-30 28 {1894}-09-18 10-12 11-01 11-10
MASON-CITY 30 {1915}-08-30 28 {1923}-09-14 10-10 10-28 11-09
DECORAH-2-N 32 {1915}-08-30 28 {1946}-09-02 10-10 11-01 11-11
ALLISON 32 {1915}-08-30 28 {1926}-09-25 10-17 11-02 11-11
Waterloo Area 32 {1917}-09-11 28 {1929}-09-18 10-13 11-02 11-11
KEOSAUQUA 31 {1917}-09-11 28 {1916}-09-18 10-24 11-10 11-22
BELLE-PLAINE 31 {1917}-09-11 28 {1916,1929}-09-18 10-17 11-03 11-12
MAQUOKETA-2-W 31 {1917}-09-11 28 {1983}-09-23 10-17 11-02 11-12
WATERLOO 32 {1917}-09-11 28 {1929}-09-18 10-13 11-02 11-10
FAIRFIELD 32 {1917}-09-11 28 {1918}-09-21 10-24 11-08 11-22
WILLIAMSBURG 32 {1917}-09-11 28 {1991}-09-20 10-18 11-03 11-12
TOLEDO 31 {1917}-09-11 27 {1896}-09-20 10-17 11-02 11-11
Burlington Airport 30 {1918}-09-18 25 {1942}-09-28 10-27 11-10 11-24
Iowa Drought Region 5 - Southeast 32 {1918}-09-21 24 {1942}-09-28 10-25 11-08 11-21
Iowa - South Central Climate Division 32 {1918}-09-21 25 {1942}-09-28 10-25 11-08 11-21
Postville 32 {1919}-09-02 20 {1918}-09-21 10-17 11-02 11-11
Iowa City 32 {1923}-09-14 28 {1916}-09-18 10-19 11-06 11-21
Estherville 4E 32 {1924}-09-09 27 {1929}-09-18 10-07 10-27 11-06
Creston 31 {1924}-09-15 28 {1991}-09-19 10-18 11-03 11-13
Iowa - Central Climate Division 31 {1929}-09-18 28 {1913}-09-22 10-19 11-03 11-11
Iowa - East Central Climate Division 32 {1929}-09-18 28 {1926}-09-26 10-20 11-06 11-21
NEWTON 32 {1929}-09-18 23 {1942}-09-28 10-20 11-06 11-21
WAUKON 32 {1937,2011}-09-16 25 {1942}-09-25 10-13 11-02 11-10
SHENANDOAH-1-NE 32 {1937}-09-16 28 {1918}-09-20 10-19 11-07 11-21
RED-OAK 32 {1940}-09-11 28 {1995}-09-22 10-19 11-03 11-21
Le Claire L&D 14 32 {1942}-09-26 28 {1942}-09-28 10-28 11-11 11-23
POCAHONTAS 31 {1946}-09-02 27 {1929}-09-18 10-10 10-28 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
FOREST-CITY 31 {1949}-09-01 27 {1929}-09-18 10-13 10-28 11-10
OSAGE 30 {1949}-09-14 28 {1929}-09-18 10-13 11-01 11-10
SIBLEY-5-NNE 30 {1950}-08-20 23 {1955}-09-11 10-07 10-26 11-03
NORTHWOOD 32 {1953}-09-13 28 {1929}-09-18 10-10 10-28 11-08
HAMPTON-2-NW 32 {1955}-09-11 28 {1955}-09-12 10-12 11-01 11-10
Oelwein Area 28 {1955}-09-11 28 {1955}-09-11 10-10 11-02 11-11
MAPLETON NO. 2 31 {1955}-09-11 27 {1991}-09-19 10-15 11-02 11-10
WEBSTER-CITY 30 {1955}-09-11 25 {1929}-09-18 10-12 10-28 11-10
Le Mars 31 {1955}-09-11 28 {1902}-09-12 10-12 10-29 11-08
COLUMBUS JUNCT 2 SSW 31 {1955}-09-12 28 {1991}-09-20 10-24 11-08 11-22
PERRY 32 {1955}-09-12 27 {1929}-09-18 10-17 11-02 11-11
CHARITON 32 {1955}-09-12 28 {1918,1991}-09-20 10-17 11-05 11-21
WINTERSET 31 {1955}-09-12 26 {1896}-09-20 10-19 11-07 11-21
MARSHALLTOWN 31 {1955}-09-12 28 {1896}-09-20 10-13 11-02 11-11
DUBUQUE-LOCK-AND-DAM 31 {1956}-09-20 24 {1899}-09-30 10-25 11-10 11-22
GUTTENBERG-L-AND-D-10 32 {1973}-09-18 25 {1942}-09-28 10-24 11-07 11-21
SAC-CITY 32 {1974}-09-03 28 {1918}-09-20 10-16 11-01 11-11
CHEROKEE 31 {1974}-09-03 27 {1955}-09-11 10-07 10-27 11-07
ROCK-RAPIDS 31 {1974}-09-03 26 {1894}-09-10 10-07 10-24 11-05
Spencer 31 {1974}-09-03 28 {2007}-09-15 10-09 10-27 11-08
SANBORN 32 {1974}-09-03 25 {1929}-09-18 10-10 10-27 11-07
Milford 32 {1974}-09-03 28 {1929}-09-18 10-10 10-31 11-08
OAKLAND-2-E 32 {1974}-09-03 28 {1995}-09-22 10-17 11-03 11-11
SWEA CITY 4 W 32 {1974}-09-03 26 {1974}-09-22 10-09 10-29 11-10
SIOUX-RAPIDS 31 {1974}-09-03 28 {1991}-09-19 10-09 10-27 11-07
FORT-DODGE 32 {1974}-09-03 27 {1902}-09-13 10-16 11-02 11-11
SIOUX CENTER 2 SE 31 {1974}-09-03 24 {1991}-09-19 10-16 10-28 11-10
CARROLL-2-SSW 28 {1974}-09-03 28 {1974}-09-03 10-16 10-28 11-10
Ida Grove Area 32 {1974}-09-03 27 {1918}-09-20 10-16 10-28 11-10
Boone 32 {1975}-09-12 27 {1929}-09-18 10-17 11-02 11-11
GRINNELL-3-SW 31 {1976}-09-10 27 {1991}-09-20 10-17 11-02 11-11
GREENFIELD 32 {1981}-09-17 27 {1913}-09-22 10-19 11-08 11-21
BURLINGTON 32 {1984}-09-26 28 {1974}-10-02 10-28 11-11 11-27
BELLEVUE-L-AND-D-12 32 {1986}-08-30 28 {1974,1995}-09-23 10-17 11-06 11-21
BEACONSFIELD 27 {1991}-09-19 27 {1991}-09-19 10-19 11-05 11-20
Allerton 31 {1991}-09-19 27 {1913}-09-22 10-19 11-08 11-21
IOWA CITY MUNICIPAL AP 32 {1991}-09-20 26 {1995}-09-23 10-19 11-07 11-21
Donnellson 31 {1991}-09-20 25 {1942}-09-28 10-19 11-10 11-22
MUSCATINE 29 {1991}-09-20 23 {1942}-09-28 10-25 11-10 11-21
Des Moines Airport 31 {1995}-09-22 26 {1942}-09-28 10-24 11-08 11-21
Des Moines Area 31 {1995}-09-22 26 {1942}-09-28 10-24 11-08 11-21
DES MOINES WSFO-JOHNSTON 31 {1999}-09-21 28 {2004}-10-02 10-21 11-10 11-12
MUSCATINE 2N 27 {2003}-10-02 27 {2003}-10-02 10-17 11-11 11-22
Emmetsburg 0 {2005}-09-03 0 {2005}-09-03 10-13 11-01 11-10
Dubuque Area 32 {2007}-09-15 28 {1956}-09-20 10-19 11-05 11-21
Cedar Rapids Airport 31 {2007}-09-15 28 {2012}-09-24 10-17 11-05 11-13
Dubuque Airport 32 {2007}-09-15 28 {1956}-09-20 10-16 11-03 11-13
OSCEOLA-3-WSW 31 {2007}-09-15 28 {1974}-09-22 10-19 11-07 11-21
LITTLE SIOUX 2NW 31 {2007}-09-15 27 {2012}-09-23 10-08 10-25 11-01
AMES MUNICIPAL AP 31 {2007}-09-15 27 {2003}-09-30 10-14 10-31 11-11
Cedar Rapids Area 31 {2007}-09-15 28 {2012}-09-24 10-18 11-03 11-19
CEDAR-RAPIDS-1 32 {2007}-09-15 24 {1926}-09-26 10-20 11-06 11-21
MARSHALLTOWN MUNICIPAL AP 30 {2007}-09-15 27 {2012}-09-23 10-14 10-31 11-11
Ottumwa 32 {2007}-09-15 23 {1942}-09-28 10-24 11-09 11-22
Spencer Area -1 {2010}-08-16 -1 {2010}-08-16 10-09 10-27 11-08
Spencer Airport -1 {2010}-08-16 -1 {2010}-08-16 10-09 10-26 11-10
LAMONI -1 {2011,2012}-08-07 -1 {2011,2012}-08-07 10-26 11-11 11-21
OELWEIN 1E 32 {2011}-09-15 28 {2012}-10-05 10-13 10-28 11-11
RATHBUN DAM 0 {2012}-08-09 0 {2012}-08-09 10-17 11-07 11-21
DAVENPORT WFO 30 {2012}-09-23 27 {2012}-10-05 10-15 10-29 11-11
SIOUX CITY ANG 31 {2012}-09-23 20 {2004}-10-02 10-11 10-27 11-10
ANAMOSA 3 SSW 30 {2012}-09-24 26 {2015}-10-17 10-15 10-29 11-12
LOWDEN 32 {2014}-09-13 26 {2012}-09-24 10-14 11-01 11-11
MANCHESTER-2 32 {2014}-09-13 27 {1984}-09-16 10-13 11-02 11-11
ESTHERVILLE MUNICIPAL AP 31 {2014}-09-13 28 {2007}-09-15 10-10 10-26 11-07
BATTLE CREEK 3NE 32 {2014}-09-13 24 {2012}-09-23 10-04 10-17 10-31
STANLEY 31 {2014}-09-13 26 {2012}-09-23 10-11 10-27 11-01
MASON CITY MUNICIPAL AP 31 {2014}-09-13 26 {2011}-09-15 10-09 10-28 11-07
HOLSTEIN 5 NNW 30 {2020}-10-02 28 {2019}-10-12 10-08 10-15 10-27
CASCADE 32 {2023}-08-31 28 {1953,1974}-09-22 10-10 11-03 11-11