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
Spencer Airport 32 {2014}-09-13 28 {2007}-09-15 10-04 10-24 11-10
SIBLEY-5-NNE 30 {1950}-08-20 23 -09-11 10-07 10-26 11-03
CHEROKEE 31 {1974}-09-03 27 -09-11 10-07 10-27 11-07
ROCK-RAPIDS 31 {1974}-09-03 26 {1894}-09-10 10-07 10-24 11-05
Estherville 4E 32 {1924}-09-09 27 {1929}-09-18 10-07 10-27 11-06
LITTLE SIOUX 2NW 31 {2007}-09-15 27 {2012}-09-23 10-08 10-25 11-11
Elkader 6SSW (Osborn) 32 {1893}-08-29 0 {2002}-09-02 10-09 10-27 11-10
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
SWEA CITY 4 W 32 {1974}-09-03 26 {1974}-09-22 10-09 10-29 11-10
Spencer Area 31 {1974}-09-03 28 {2007}-09-15 10-09 10-27 11-08
MASON CITY MUNICIPAL AP 31 {2014}-09-13 26 {2011}-09-15 10-09 10-28 11-07
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
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
SANBORN 32 {1974}-09-03 25 {1929}-09-18 10-10 10-27 11-07
CASCADE 32 -09-11 28 {1953,1974}-09-22 10-10 11-03 11-11
ESTHERVILLE MUNICIPAL AP 31 {2014}-09-13 28 {2007}-09-15 10-10 10-24 11-07
STANLEY 31 {2014}-09-13 26 {2012}-09-23 10-11 10-26 11-11
IOWA-FALLS 31 {1915}-08-30 28 {1894}-09-18 10-12 11-01 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
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
Iowa - North Central Climate Division 32 {1902}-09-13 28 {1929}-09-18 10-12 11-01 11-10
ROCK VALLEY 32 {2007,2011}-09-15 28 {1995}-09-22 10-12 10-31 11-10
SIOUX CITY ANG 31 {2012}-09-23 20 {2004}-10-02 10-12 10-26 11-10
HOLSTEIN 5 NNW 30 {2020}-10-02 28 {2019}-10-12 10-12 10-25 11-10
NEW-HAMPTON 28 {1949}-09-01 28 {1949}-09-01 10-13 11-01 11-10
FOREST-CITY 31 {1949}-09-01 27 {1929}-09-18 10-13 10-28 11-09
Milford 32 {1974}-09-03 28 {1929}-09-18 10-13 10-31 11-08
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
HAMPTON-2-NW 32 -09-11 28 {1955}-09-12 10-13 11-01 11-10
MARSHALLTOWN 31 {1955}-09-12 28 {1896}-09-20 10-13 11-02 11-11
Emmetsburg 32 {1902}-09-12 28 {1929}-09-18 10-13 11-01 11-10
GRUNDY-CENTER 32 {1902}-09-12 28 {1929}-09-18 10-13 11-02 11-11
MANCHESTER-2 32 {2014}-09-13 27 {1984}-09-16 10-13 11-02 11-11
LOWDEN 32 {2014}-09-13 26 {2012}-09-24 10-13 11-01 11-11
Iowa - Northeast Climate Division 32 {1902}-09-13 28 {1974}-09-22 10-13 11-02 11-11
OSAGE 30 {1949}-09-14 28 {1929}-09-18 10-13 11-01 11-10
AMES MUNICIPAL AP 31 {2007}-09-15 27 {2003}-09-30 10-13 10-31 11-11
OELWEIN 1E 32 {2011}-09-15 28 {2012}-10-05 10-13 10-29 11-11
ANAMOSA 3 SSW 30 {2012}-09-24 26 {2015}-10-17 10-13 10-29 11-12
MARSHALLTOWN MUNICIPAL AP 30 {2007}-09-15 27 {2012}-09-23 10-14 10-31 11-11
OGDEN 32 {2007}-09-15 26 {2003}-10-02 10-14 11-07 11-11
MAPLETON NO. 2 31 -09-11 27 {1991}-09-19 10-15 11-02 11-08
DAVENPORT WFO 30 {2012}-09-23 27 {2012}-10-05 10-15 10-29 11-11
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
SIOUX CENTER 2 SE 31 {1974}-09-03 24 {1991}-09-19 10-16 10-28 11-10
Ida Grove Area 32 {1974}-09-03 27 {1918}-09-20 10-16 10-31 11-10
Oelwein Area 20 {1942}-09-05 20 {1942}-09-05 10-16 11-02 11-11
PRIMGHAR 30 {1902}-09-12 25 {1901}-09-18 10-16 10-31 11-10
CHARLES-CITY 32 {1902,1955}-09-12 28 {1991}-09-20 10-16 11-02 11-11
JEFFERSON 32 {1893}-08-29 28 {1929}-09-18 10-17 11-02 11-11
BELLEVUE-L-AND-D-12 32 {1986}-08-30 28 {1974,1995}-09-23 10-17 11-06 11-21
ALLISON 32 {1915}-08-30 28 {1926}-09-25 10-17 11-02 11-11
ATLANTIC-1-NE 30 {1893}-09-02 28 {1902,1955}-09-12 10-17 11-01 11-10
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
ALGONA 29 {1893}-09-02 27 {1929}-09-18 10-17 11-01 11-10
FORT-DODGE 32 {1974}-09-03 27 {1902}-09-13 10-17 11-02 11-11
OAKLAND-2-E 32 {1974}-09-03 28 {1995}-09-22 10-17 11-03 11-11
GRINNELL-3-SW 31 {1976}-09-10 27 {1991}-09-20 10-17 11-02 11-11
TOLEDO 31 -09-11 27 {1896}-09-20 10-17 11-02 11-11
BELLE-PLAINE 31 -09-11 28 {1916,1929}-09-18 10-17 11-03 11-12
MAQUOKETA-2-W 31 -09-11 28 {1983}-09-23 10-17 11-03 11-12
Iowa Drought Region 2 - Northcentral 32 {1902}-09-12 27 {1913}-09-22 10-17 11-01 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
SPIRIT LAKE 31 {1902}-09-12 28 {1929}-09-18 10-17 11-01 11-10
ROCKWELL-CITY 32 {1902}-09-12 28 {1929}-09-18 10-17 11-01 11-10
PERRY 32 {1955}-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
AUDUBON 30 {1902,1955}-09-12 27 {1896}-09-19 10-17 11-01 11-10
Boone 32 {1975}-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
CORNING 32 {1902}-09-12 27 {1983}-09-21 10-17 11-03 11-13
Iowa Drought Region 3 - Northeast 32 {1902}-09-13 27 {1926}-09-26 10-17 11-03 11-12
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
SIOUX-CITY-WSO-AP 30 {1902}-09-13 25 {1995}-09-22 10-17 11-02 11-10
VINTON 32 {1902,1953}-09-13 28 {1982}-09-21 10-17 11-03 11-12
Iowa Average 32 {1902}-09-13 24 {1942}-09-28 10-17 11-02 11-11
Dubuque Airport 32 {2007}-09-15 28 {1956}-09-20 10-17 11-03 11-12
Cedar Rapids Airport 31 {2007}-09-15 28 {2012}-09-24 10-17 11-05 11-12
Iowa - Central Climate Division 32 {2007}-09-15 28 {1913}-09-22 10-17 11-02 11-11
MUSCATINE 2N 27 {2003}-10-02 27 {2003}-10-02 10-17 11-11 11-22
WILLIAMSBURG 32 -09-11 28 {1991}-09-20 10-18 11-03 11-12
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 11-03 11-12
Cedar Rapids Area 31 {2007}-09-15 28 {2012}-09-24 10-18 11-03 11-19
Creston 31 {1924}-09-15 28 {1991}-09-19 10-18 11-03 11-13
Iowa - East Central Climate Division 32 {1929}-09-18 28 {1926}-09-26 10-18 11-05 11-21
RATHBUN DAM 32 {1974}-09-22 28 {1985}-10-01 10-18 11-08 11-21
RED-OAK 32 -09-11 28 {1995}-09-22 10-19 11-03 11-21
Iowa Drought Region 4 - Southwest 32 {1902}-09-12 26 {1942}-09-28 10-19 11-03 11-13
WINTERSET 31 {1955}-09-12 26 {1896}-09-20 10-19 11-07 11-21
MOUNT-AYR 32 {1902}-09-13 28 {1991}-09-19 10-19 11-05 11-19
OSKALOOSA 31 {1902}-09-13 27 {1991}-09-20 10-19 11-08 11-21
WASHINGTON 30 {1902}-09-13 28 {1983}-09-23 10-19 11-08 11-21
Iowa - Southwest Climate Division 32 {1902}-09-13 26 {1942}-09-28 10-19 11-05 11-19
CLARINDA 31 {1902}-09-13 28 {1918}-09-21 10-19 11-03 11-19
SIGOURNEY 32 {1902}-09-13 25 {1913}-09-21 10-19 11-08 11-21
AMES 5 SE 32 {1902}-09-13 28 {1926}-09-26 10-19 11-04 11-20
Iowa City 32 {1923}-09-14 28 {1916}-09-18 10-19 11-06 11-21
Dubuque Area 32 {2007}-09-15 28 {1956}-09-20 10-19 11-05 11-21
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
GREENFIELD 32 {1981}-09-17 27 {1913}-09-22 10-19 11-08 11-21
GUTTENBERG-L-AND-D-10 32 {1973}-09-18 25 {1942}-09-28 10-19 11-07 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 - South Central Climate Division 32 {1991}-09-19 25 {1942}-09-28 10-19 11-08 11-21
Donnellson 31 {1991}-09-20 25 {1942}-09-28 10-19 11-10 11-22
IOWA CITY MUNICIPAL AP 32 {1991}-09-20 26 {1995}-09-23 10-19 11-07 11-21
Iowa Drought Region 5 - Southeast 32 {1991}-09-20 24 {1942}-09-28 10-19 11-08 11-21
CLINTON-1 31 {1902}-09-13 28 {1928}-09-25 10-20 11-09 11-22
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
DES MOINES WSFO-JOHNSTON 31 {1999}-09-21 28 {2004}-10-02 10-21 11-10 11-12
KEOSAUQUA 31 -09-11 28 {1916}-09-18 10-24 11-09 11-22
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
Ottumwa 32 {2007}-09-15 23 {1942}-09-28 10-24 11-09 11-22
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
MUSCATINE 29 {1991}-09-20 23 {1942}-09-28 10-24 11-10 11-21
Iowa - Southeast Climate Division 32 {1896}-09-20 25 {1942}-09-28 10-24 11-08 11-22
Des Moines Area 31 {1995}-09-22 26 {1942}-09-28 10-24 11-08 11-21
Des Moines Airport 31 {1995}-09-22 26 {1942}-09-28 10-24 11-08 11-21
LAMONI 29 {2004}-10-02 27 {2012}-10-06 10-24 11-10 11-20
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
DUBUQUE-LOCK-AND-DAM 31 {1956}-09-20 24 {1899}-09-30 10-25 11-10 11-22
Burlington Airport 30 {1918}-09-18 25 {1942}-09-28 10-27 11-10 11-24
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
NORTHWOOD -10 {1929}-11-29 -10 {1929}-11-29 11-29 11-29 11-29