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.

Select Network:
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:
ROCK-RAPIDS 31 {1974}-09-03 26 {1894}-09-10 10-07 10-24 11-05
IOWA-FALLS 31 {1915}-08-30 28 {1894}-09-18 10-12 11-01 11-10
AUDUBON 30 {1902,1955}-09-12 27 {1896}-09-19 10-17 11-01 11-10
TOLEDO 31 {1917}-09-11 27 {1896}-09-20 10-17 11-02 11-11
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
PRIMGHAR 30 {1902}-09-12 25 {1901}-09-18 10-16 10-31 11-10
ATLANTIC-1-NE 30 {1893}-09-02 28 {1902,1955}-09-12 10-16 11-01 11-10
FAYETTE 32 {1949}-09-01 27 {1902}-09-12 10-10 10-28 11-10
Le Mars 31 {1955}-09-11 28 {1902}-09-12 10-12 10-29 11-08
FORT-DODGE 32 {1974}-09-03 27 {1902}-09-13 10-16 11-02 11-11
LOGAN 30 {1902}-09-12 28 {1902}-09-13 10-17 11-02 11-11
SIGOURNEY 32 {1902}-09-13 25 {1913}-09-21 10-19 11-08 11-22
Iowa Drought Region 2 - Northcentral 32 {1902}-09-12 27 {1913}-09-22 10-17 11-02 11-11
CENTERVILLE 31 {1913}-09-13 28 {1913}-09-22 10-25 11-10 11-22
GREENFIELD 32 {1981}-09-17 27 {1913}-09-22 10-19 11-08 11-21
Iowa - Central Climate Division 31 {1929}-09-18 28 {1913}-09-22 10-19 11-03 11-11
Allerton 31 {1991}-09-19 27 {1913}-09-22 10-19 11-08 11-21
BELLE-PLAINE 31 {1917}-09-11 28 {1916,1929}-09-18 10-17 11-03 11-12
KEOSAUQUA 31 {1917}-09-11 28 {1916}-09-18 10-24 11-10 11-22
Iowa City 32 {1923}-09-14 28 {1916}-09-18 10-19 11-06 11-21
CHARITON 32 {1955}-09-12 28 {1918,1991}-09-20 10-17 11-05 11-21
SAC-CITY 32 {1974}-09-03 28 {1918}-09-20 10-16 11-01 11-11
Ida Grove Area 32 {1974}-09-03 27 {1918}-09-20 10-16 10-28 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
Iowa Drought Region 1 - Northwest 30 {1902}-09-12 25 {1918}-09-20 10-17 11-01 11-10
SHENANDOAH-1-NE 32 {1937}-09-16 28 {1918}-09-20 10-19 11-07 11-21
Postville 32 {1919}-09-02 20 {1918}-09-21 10-17 11-02 11-11
FAIRFIELD 32 {1917}-09-11 28 {1918}-09-21 10-24 11-08 11-22
DENISON 29 {1902}-09-12 21 {1918}-09-21 10-18 11-02 11-11
AMES-8-WSW 31 {1902}-09-13 26 {1918}-09-21 10-18 11-02 11-12
Ames Area 31 {1902}-09-13 26 {1918}-09-21 10-17 11-02 11-11
CLARINDA 31 {1902}-09-13 28 {1918}-09-21 10-18 11-02 11-19
MASON-CITY 30 {1915}-08-30 28 {1923}-09-14 10-10 10-28 11-09
ALLISON 32 {1915}-08-30 28 {1926}-09-25 10-17 11-02 11-11
Iowa - Northeast Climate Division 32 {1902}-09-13 26 {1926}-09-26 10-17 11-02 11-11
AMES 5 SE 32 {1902}-09-13 28 {1926}-09-26 10-19 11-04 11-20
Iowa Drought Region 3 - Northeast 32 {1902}-09-13 27 {1926}-09-26 10-19 11-03 11-12
CEDAR-RAPIDS-1 32 {2007}-09-15 24 {1926}-09-26 10-20 11-06 11-21
Iowa - East Central Climate Division 32 {1929}-09-18 28 {1926}-09-26 10-20 11-06 11-21
CLINTON-1 31 {1902}-09-13 28 {1928}-09-25 10-20 11-09 11-22
JEFFERSON 32 {1893}-08-29 28 {1929}-09-18 10-17 11-02 11-11
FOREST-CITY 31 {1949}-09-01 27 {1929}-09-18 10-13 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
Milford 32 {1974}-09-03 28 {1929}-09-18 10-10 10-31 11-08
SANBORN 32 {1974}-09-03 25 {1929}-09-18 10-10 10-27 11-07
Estherville 4E 32 {1924}-09-09 27 {1929}-09-18 10-07 10-27 11-06
WATERLOO 32 {1917}-09-11 28 {1929}-09-18 10-13 11-02 11-10
WEBSTER-CITY 30 {1955}-09-11 25 {1929}-09-18 10-12 10-28 11-10
Waterloo Area 32 {1917}-09-11 28 {1929}-09-18 10-13 11-02 11-11
Boone 32 {1975}-09-12 27 {1929}-09-18 10-17 11-02 11-11
PERRY 32 {1955}-09-12 27 {1929}-09-18 10-17 11-02 11-11
SPIRIT LAKE 31 {1902}-09-12 28 {1929}-09-18 10-17 11-01 11-10
GRUNDY-CENTER 32 {1902}-09-12 28 {1929}-09-18 10-13 11-02 11-11
STORM-LAKE-2-E 32 {1902}-09-12 28 {1929}-09-18 10-17 11-01 11-10
NORTHWOOD 32 {1953}-09-13 28 {1929}-09-18 10-10 10-28 11-08
Iowa - North Central Climate Division 32 {1902,2014}-09-13 28 {1929}-09-18 10-17 11-02 11-10
OSAGE 30 {1949}-09-14 28 {1929}-09-18 10-13 11-01 11-10
MOUNT-PLEASANT 32 {1902}-09-13 28 {1942}-09-24 10-25 11-10 11-22
WAUKON 32 {1937,2011}-09-16 25 {1942}-09-25 10-13 11-02 11-10
Iowa Drought Region 4 - Southwest 32 {1902}-09-12 26 {1942}-09-28 10-19 11-05 11-19
Iowa Average 32 {1902}-09-13 24 {1942}-09-28 10-19 11-03 11-11
Iowa - Southwest Climate Division 32 {1902}-09-13 26 {1942}-09-28 10-24 11-08 11-21
Ottumwa 32 {2007}-09-15 23 {1942}-09-28 10-24 11-09 11-22
Lamoni 32 {1901}-09-18 27 {1942}-09-28 10-24 11-08 11-21
Burlington Airport 30 {1918}-09-18 25 {1942}-09-28 10-27 11-10 11-24
GUTTENBERG-L-AND-D-10 32 {1973}-09-18 25 {1942}-09-28 10-24 11-07 11-21
NEWTON 32 {1929}-09-18 23 {1942}-09-28 10-20 11-06 11-21
Iowa - Southeast Climate Division 32 {1896}-09-20 25 {1942}-09-28 10-25 11-09 11-22
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
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
Des Moines Airport 31 {1995}-09-22 26 {1942}-09-28 10-24 11-08 11-21
Fort Madison 32 {1913}-09-22 26 {1942}-09-28 10-27 11-11 11-24
Des Moines Area 31 {1995}-09-22 26 {1942}-09-28 10-24 11-08 11-21
Le Claire L&D 14 32 {1942}-09-26 28 {1942}-09-28 10-28 11-11 11-23
DECORAH-2-N 32 {1915}-08-30 28 {1946}-09-02 10-10 11-01 11-11
NEW-HAMPTON 28 {1949}-09-01 28 {1949}-09-01 10-13 11-01 11-10
KEOKUK LOCK DAM 19 30 {1992}-09-23 23 {1952}-10-06 11-02 11-13 11-28
CASCADE 32 {2023}-08-31 28 {1953,1974}-09-22 10-10 11-03 11-11
SIBLEY-5-NNE 30 {1950}-08-20 23 {1955}-09-11 10-07 10-26 11-03
CHEROKEE 31 {1974}-09-03 27 {1955}-09-11 10-07 10-27 11-07
Oelwein Area 28 {1955}-09-11 28 {1955}-09-11 10-10 11-02 11-11
HAMPTON-2-NW 32 {1955}-09-11 28 {1955}-09-12 10-12 11-01 11-10
Dubuque Airport 32 {2007}-09-15 28 {1956}-09-20 10-16 11-03 11-13
Dubuque Area 32 {2007}-09-15 28 {1956}-09-20 10-19 11-05 11-21
BELLEVUE-L-AND-D-12 32 {1986}-08-30 28 {1974,1995}-09-23 10-17 11-06 11-21
CARROLL-2-SSW 28 {1974}-09-03 28 {1974}-09-03 10-16 10-28 11-10
SWEA CITY 4 W 32 {1974}-09-03 26 {1974}-09-22 10-09 10-29 11-10
OSCEOLA-3-WSW 31 {2007}-09-15 28 {1974}-09-22 10-19 11-07 11-21
BURLINGTON 32 {1984}-09-26 28 {1974}-10-02 10-28 11-11 11-27
VINTON 32 {1902,1953}-09-13 28 {1982}-09-21 10-17 11-03 11-12
CORNING 32 {1902}-09-12 27 {1983}-09-21 10-17 11-03 11-13
MAQUOKETA-2-W 31 {1917}-09-11 28 {1983}-09-23 10-17 11-02 11-12
WASHINGTON 30 {1902}-09-13 28 {1983}-09-23 10-24 11-08 11-21
MANCHESTER-2 32 {2014}-09-13 27 {1984}-09-16 10-13 11-02 11-11
SIOUX-RAPIDS 31 {1974}-09-03 28 {1991}-09-19 10-09 10-27 11-07
SIOUX CENTER 2 SE 31 {1974}-09-03 24 {1991}-09-19 10-16 10-28 11-10
MAPLETON NO. 2 31 {1955}-09-11 27 {1991}-09-19 10-15 11-02 11-10
GUTHRIE-CENTER 31 {1902}-09-12 28 {1991}-09-19 10-17 11-02 11-11
MOUNT-AYR 32 {1902}-09-13 28 {1991}-09-19 10-19 11-05 11-19
Creston 31 {1924}-09-15 28 {1991}-09-19 10-18 11-03 11-13
BEACONSFIELD 27 {1991}-09-19 27 {1991}-09-19 10-19 11-05 11-20
GRINNELL-3-SW 31 {1976}-09-10 27 {1991}-09-20 10-17 11-02 11-11
WILLIAMSBURG 32 {1917}-09-11 28 {1991}-09-20 10-18 11-03 11-12
COLUMBUS JUNCT 2 SSW 31 {1955}-09-12 28 {1991}-09-20 10-24 11-08 11-22
CHARLES-CITY 32 {1902,1955}-09-12 28 {1991}-09-20 10-16 11-02 11-11
OSKALOOSA 31 {1902}-09-13 27 {1991}-09-20 10-19 11-08 11-21
OAKLAND-2-E 32 {1974}-09-03 28 {1995}-09-22 10-17 11-03 11-11
RED-OAK 32 {1940}-09-11 28 {1995}-09-22 10-19 11-03 11-21
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
IOWA CITY MUNICIPAL AP 32 {1991}-09-20 26 {1995}-09-23 10-19 11-07 11-21
Elkader 6SSW (Osborn) 32 {1893}-08-29 0 {2002}-09-02 10-09 10-28 11-10
AMES MUNICIPAL AP 31 {2007}-09-15 27 {2003}-09-30 10-14 10-31 11-11
MUSCATINE 2N 27 {2003}-10-02 27 {2003}-10-02 10-17 11-11 11-22
DES MOINES WSFO-JOHNSTON 31 {1999}-09-21 28 {2004}-10-02 10-21 11-10 11-12
SIOUX CITY ANG 31 {2012}-09-23 20 {2004}-10-02 10-11 10-27 11-10
Emmetsburg 0 {2005}-09-03 0 {2005}-09-03 10-13 11-01 11-10
Spencer 31 {1974}-09-03 28 {2007}-09-15 10-09 10-27 11-08
ESTHERVILLE MUNICIPAL AP 31 {2014}-09-13 28 {2007}-09-15 10-10 10-26 11-07
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
MASON CITY MUNICIPAL AP 31 {2014}-09-13 26 {2011}-09-15 10-09 10-28 11-07
RATHBUN DAM 0 {2012}-08-09 0 {2012}-08-09 10-17 11-07 11-21
STANLEY 31 {2014}-09-13 26 {2012}-09-23 10-11 10-27 11-01
BATTLE CREEK 3NE 32 {2014}-09-13 24 {2012}-09-23 10-04 10-17 10-31
MARSHALLTOWN MUNICIPAL AP 30 {2007}-09-15 27 {2012}-09-23 10-14 10-31 11-11
LITTLE SIOUX 2NW 31 {2007}-09-15 27 {2012}-09-23 10-08 10-25 11-01
LOWDEN 32 {2014}-09-13 26 {2012}-09-24 10-14 11-01 11-11
Cedar Rapids Area 31 {2007}-09-15 28 {2012}-09-24 10-18 11-03 11-19
Cedar Rapids Airport 31 {2007}-09-15 28 {2012}-09-24 10-17 11-05 11-13
OELWEIN 1E 32 {2011}-09-15 28 {2012}-10-05 10-13 10-28 11-11
DAVENPORT WFO 30 {2012}-09-23 27 {2012}-10-05 10-15 10-29 11-11
ANAMOSA 3 SSW 30 {2012}-09-24 26 {2015}-10-17 10-15 10-29 11-12
HOLSTEIN 5 NNW 30 {2020}-10-02 28 {2019}-10-12 10-08 10-15 10-27