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
ESTHERVILLE MUNICIPAL AP 31 {2014}-09-13 28 {2007}-09-15 10-10 10-24 11-07
Spencer Airport 32 {2014}-09-13 28 {2007}-09-15 10-04 10-24 11-10
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
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
Spencer 31 {1974}-09-03 28 {2007}-09-15 10-09 10-27 11-08
Spencer Area 31 {1974}-09-03 28 {2007}-09-15 10-09 10-27 11-08
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
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 11-09
POCAHONTAS 31 {1946}-09-02 27 {1929}-09-18 10-10 10-28 11-10
SIOUX CENTER 2 SE 31 {1974}-09-03 24 {1991}-09-19 10-16 10-28 11-10
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
LEMARS 31 -09-11 28 {1902}-09-12 10-12 10-28 11-08
WEBSTER-CITY 30 -09-11 25 {1929}-09-18 10-12 10-28 11-10
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
CARROLL-2-SSW 28 {1974}-09-03 28 {1974}-09-03 10-16 11-01 11-10
SAC-CITY 32 {1974}-09-03 28 {1918}-09-20 10-16 11-01 11-11
HAMPTON-2-NW 32 -09-11 28 {1955}-09-12 10-13 11-01 11-10
Iowa Drought Region 2 - Northcentral 32 {1902}-09-12 27 {1913}-09-22 10-17 11-01 11-11
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
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
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
GUTHRIE-CENTER 31 {1893}-09-02 28 {1991}-09-19 10-17 11-02 11-11
Postville 32 {1919}-09-02 20 {1918}-09-21 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
MAPLETON NO. 2 31 -09-11 27 {1991}-09-19 10-15 11-02 11-08
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
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
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
STORM-LAKE-2-E 32 {1902}-09-12 28 {1929}-09-18 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
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
Iowa Average 32 {1902}-09-13 24 {1942}-09-28 10-17 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
BELLE-PLAINE 31 -09-11 28 {1916,1929}-09-18 10-17 11-03 11-12
CASCADE 32 -09-11 28 {1953,1974}-09-22 10-10 11-03 11-11
MAQUOKETA-2-W 31 -09-11 28 {1983}-09-23 10-17 11-03 11-12
RED-OAK 32 -09-11 28 {1995}-09-22 10-19 11-03 11-21
WILLIAMSBURG 32 -09-11 28 {1991}-09-20 10-18 11-03 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
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
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
Creston 31 {1924}-09-15 28 {1991}-09-19 10-18 11-03 11-13
Dubuque Airport 32 {2007}-09-15 28 {1956}-09-20 10-17 11-03 11-12
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
CHARITON 32 {1955}-09-12 28 {1918,1991}-09-20 10-17 11-05 11-21
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
Cedar Rapids Airport 31 {2007}-09-15 28 {2012}-09-24 10-17 11-05 11-12
Dubuque Area 32 {2007}-09-15 28 {1956}-09-20 10-19 11-05 11-21
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
OGDEN 32 {2007}-09-15 26 {2003}-10-02 10-14 11-07 11-11
OSCEOLA-3-WSW 31 {2007}-09-15 28 {1974}-09-22 10-19 11-07 11-21
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
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
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 - Southeast Climate Division 32 {1896}-09-20 25 {1942}-09-28 10-24 11-08 11-22
Iowa Drought Region 5 - Southeast 32 {1991}-09-20 24 {1942}-09-28 10-19 11-08 11-21
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
CENTERVILLE 31 {1913}-09-13 28 {1913}-09-22 10-25 11-10 11-22
MOUNT-PLEASANT 32 {1902}-09-13 28 {1942}-09-24 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