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