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:
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
FAIRFIELD 32 -09-11 28 {1918}-09-21 10-24 11-08 11-22
HAMPTON-2-NW 32 -09-11 28 {1955}-09-12 10-13 11-01 11-10
KEOSAUQUA 31 -09-11 28 {1916}-09-18 10-24 11-09 11-22
LEMARS 31 -09-11 28 {1902}-09-12 10-12 10-28 11-08
MAPLETON NO. 2 31 -09-11 27 {1991}-09-19 10-15 11-02 11-08
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
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
WEBSTER-CITY 30 -09-11 25 {1929}-09-18 10-12 10-28 11-10
WILLIAMSBURG 32 -09-11 28 {1991}-09-20 10-18 11-03 11-12
Waterloo Area 32 -09-11 28 {1929}-09-18 10-13 11-02 11-11
Elkader 6SSW (Osborn) 32 {1893}-08-29 0 {2002}-09-02 10-09 10-27 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 10-17 11-01 11-10
ALGONA 29 {1893}-09-02 27 {1929}-09-18 10-17 11-01 11-10
GUTHRIE-CENTER 31 {1893}-09-02 28 {1991}-09-19 10-17 11-02 11-11
Iowa - Southeast Climate Division 32 {1896}-09-20 25 {1942}-09-28 10-24 11-08 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 - West Central Climate Division 31 {1902}-09-12 28 {1918}-09-20 10-17 11-02 11-11
Iowa Drought Region 2 - Northcentral 32 {1902}-09-12 27 {1913}-09-22 10-17 11-01 11-11
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
DENISON 29 {1902}-09-12 21 {1918}-09-21 10-18 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
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
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
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-8-WSW 31 {1902}-09-13 26 {1918}-09-21 10-18 11-03 11-12
AMES 5 SE 32 {1902}-09-13 28 {1926}-09-26 10-19 11-04 11-20
CLARINDA 31 {1902}-09-13 28 {1918}-09-21 10-19 11-03 11-19
CLINTON-1 31 {1902}-09-13 28 {1928}-09-25 10-20 11-09 11-22
MOUNT-AYR 32 {1902}-09-13 28 {1991}-09-19 10-19 11-05 11-19
MOUNT-PLEASANT 32 {1902}-09-13 28 {1942}-09-24 10-25 11-10 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
SIOUX-CITY-WSO-AP 30 {1902}-09-13 25 {1995}-09-22 10-17 11-02 11-10
WASHINGTON 30 {1902}-09-13 28 {1983}-09-23 10-19 11-08 11-21
Iowa - North Central Climate Division 32 {1902}-09-13 28 {1929}-09-18 10-12 11-01 11-10
Iowa - Northeast Climate Division 32 {1902}-09-13 28 {1974}-09-22 10-13 11-02 11-11
Iowa - Southwest Climate Division 32 {1902}-09-13 26 {1942}-09-28 10-19 11-05 11-19
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
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
ALLISON 32 {1915}-08-30 28 {1926}-09-25 10-17 11-02 11-11
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
MASON-CITY 30 {1915}-08-30 28 {1923}-09-14 10-10 10-28 11-09
KNOXVILLE 31 {1916}-09-18 28 {1926}-09-26 10-24 11-08 11-21
Burlington Airport 30 {1918}-09-18 25 {1942}-09-28 10-27 11-10 11-24
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
NEWTON 32 {1929}-09-18 23 {1942}-09-28 10-20 11-06 11-21
Iowa - East Central Climate Division 32 {1929}-09-18 28 {1926}-09-26 10-18 11-05 11-21
NORTHWOOD -10 {1929}-11-29 -10 {1929}-11-29 11-29 11-29 11-29
SHENANDOAH-1-NE 32 {1937}-09-16 28 {1918}-09-20 10-19 11-07 11-21
LAKE PARK 30 {1940}-09-12 28 {1916}-09-15 10-12 10-28 11-08
Oelwein Area 20 {1942}-09-05 20 {1942}-09-05 10-16 11-02 11-11
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
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
NEW-HAMPTON 28 {1949}-09-01 28 {1949}-09-01 10-13 11-01 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 -09-11 10-07 10-26 11-03
WINTERSET 31 {1955}-09-12 26 {1896}-09-20 10-19 11-07 11-21
CHARITON 32 {1955}-09-12 28 {1918,1991}-09-20 10-17 11-05 11-21
COLUMBUS JUNCT 2 SSW 31 {1955}-09-12 28 {1991}-09-20 10-24 11-08 11-22
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
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 10-19 11-07 11-21
CARROLL-2-SSW 28 {1974}-09-03 28 {1974}-09-03 10-16 11-01 11-10
CHEROKEE 31 {1974}-09-03 27 -09-11 10-07 10-27 11-07
FORT-DODGE 32 {1974}-09-03 27 {1902}-09-13 10-17 11-02 11-11
Milford 32 {1974}-09-03 28 {1929}-09-18 10-13 10-31 11-08
OAKLAND-2-E 32 {1974}-09-03 28 {1995}-09-22 10-17 11-03 11-11
ROCK-RAPIDS 31 {1974}-09-03 26 {1894}-09-10 10-07 10-24 11-05
SAC-CITY 32 {1974}-09-03 28 {1918}-09-20 10-16 11-01 11-11
SANBORN 32 {1974}-09-03 25 {1929}-09-18 10-10 10-27 11-07
SIOUX CENTER 2 SE 31 {1974}-09-03 24 {1991}-09-19 10-16 10-28 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
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
Ida Grove Area 32 {1974}-09-03 27 {1918}-09-20 10-16 10-31 11-10
Spencer Area 31 {1974}-09-03 28 {2007}-09-15 10-09 10-27 11-08
RATHBUN DAM 32 {1974}-09-22 28 {1985}-10-01 10-18 11-08 11-21
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 10-27 11-11 11-27
BELLEVUE-L-AND-D-12 32 {1986}-08-30 28 {1974,1995}-09-23 10-17 11-06 11-21
Allerton 31 {1991}-09-19 27 {1913}-09-22 10-19 11-08 11-21
BEACONSFIELD 27 {1991}-09-19 27 {1991}-09-19 10-19 11-05 11-20
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
MUSCATINE 29 {1991}-09-20 23 {1942}-09-28 10-24 11-10 11-21
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
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
LAMONI 29 {2004}-10-02 27 {2012}-10-06 10-24 11-10 11-20
ROCK VALLEY 32 {2007,2011}-09-15 28 {1995}-09-22 10-12 10-31 11-10
AMES MUNICIPAL AP 31 {2007}-09-15 27 {2003}-09-30 10-13 10-31 11-11
Cedar Rapids Airport 31 {2007}-09-15 28 {2012}-09-24 10-17 11-05 11-12
CEDAR-RAPIDS-1 32 {2007}-09-15 24 {1926}-09-26 10-20 11-06 11-21
Dubuque Airport 32 {2007}-09-15 28 {1956}-09-20 10-17 11-03 11-12
LITTLE SIOUX 2NW 31 {2007}-09-15 27 {2012}-09-23 10-08 10-25 11-11
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
OSCEOLA-3-WSW 31 {2007}-09-15 28 {1974}-09-22 10-19 11-07 11-21
Ottumwa 32 {2007}-09-15 23 {1942}-09-28 10-24 11-09 11-22
Iowa - Central Climate Division 32 {2007}-09-15 28 {1913}-09-22 10-17 11-02 11-11
Cedar Rapids Area 31 {2007}-09-15 28 {2012}-09-24 10-18 11-03 11-19
Dubuque Area 32 {2007}-09-15 28 {1956}-09-20 10-19 11-05 11-21
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
SIOUX CITY ANG 31 {2012}-09-23 20 {2004}-10-02 10-12 10-26 11-10
ANAMOSA 3 SSW 30 {2012}-09-24 26 {2015}-10-17 10-13 10-29 11-12
BATTLE CREEK 3NE 32 {2014}-09-13 24 {2012}-09-23 10-04 10-15 10-31
ESTHERVILLE MUNICIPAL AP 31 {2014}-09-13 28 {2007}-09-15 10-10 10-24 11-07
LOWDEN 32 {2014}-09-13 26 {2012}-09-24 10-13 11-01 11-11
MANCHESTER-2 32 {2014}-09-13 27 {1984}-09-16 10-13 11-02 11-11
MASON CITY MUNICIPAL AP 31 {2014}-09-13 26 {2011}-09-15 10-09 10-28 11-07
STANLEY 31 {2014}-09-13 26 {2012}-09-23 10-11 10-26 11-11
Spencer Airport 32 {2014}-09-13 28 {2007}-09-15 10-04 10-24 11-10
HOLSTEIN 5 NNW 30 {2020}-10-02 28 {2019}-10-12 10-12 10-25 11-10