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:
Iowa Average 32 -09-13 24 -09-28 10-17 11-02 11-12
ALGONA 29 -09-02 27 -09-18 10-17 11-01 11-10
Allerton 31 -09-19 27 -09-22 10-19 11-08 11-21
ALLISON 32 -08-30 28 -09-25 10-17 11-02 11-11
AMES-8-WSW 31 -09-13 26 -09-21 10-18 11-02 11-12
AMES 5 SE 32 -09-13 28 -09-26 10-19 11-04 11-21
ANAMOSA 3 SSW 30 -09-24 26 -10-17 10-13 10-29 11-12
ATLANTIC-1-NE 30 -09-02 28 -09-12 10-17 11-01 11-10
AUDUBON 30 -09-12 27 -09-19 10-17 11-01 11-10
BATTLE CREEK 3NE 32 -09-13 24 -09-23 10-04 10-22 10-31
BEACONSFIELD 27 -09-19 27 -09-19 10-19 11-05 11-20
BELLE-PLAINE 31 -09-11 28 -09-18 10-17 11-03 11-12
BELLEVUE-L-AND-D-12 32 -08-30 28 -09-23 10-17 11-06 11-21
Boone 32 -09-12 27 -09-18 10-17 11-02 11-11
BURLINGTON 32 -09-26 28 -10-02 10-27 11-10 11-24
Burlington 30 -09-18 25 -09-28 10-27 11-10 11-24
CARROLL-2-SSW 28 -09-03 28 -09-03 10-16 11-01 11-10
CASCADE 32 -09-11 28 -09-22 10-10 11-03 11-11
CEDAR-RAPIDS-1 32 -09-15 24 -09-26 10-22 11-06 11-21
CENTERVILLE 31 -09-13 28 -09-22 10-25 11-10 11-22
CHARITON 32 -09-12 28 -09-20 10-17 11-05 11-21
CHARLES-CITY 32 -09-12 28 -09-20 10-16 11-02 11-11
CHEROKEE 31 -09-03 27 -09-11 10-09 10-27 11-07
CLARINDA 31 -09-13 28 -09-21 10-19 11-03 11-19
CLARION 32 -08-20 1 -08-28 10-10 11-01 11-09
CLINTON-1 31 -09-13 28 -09-25 10-20 11-09 11-22
COLUMBUS JUNCT 2 SSW 31 -09-12 28 -09-20 10-24 11-08 11-22
CORNING 32 -09-12 27 -09-21 10-17 11-03 11-13
Creston 31 -09-15 28 -09-19 10-19 11-03 11-13
Dakota City 31 -09-15 24 -10-02 10-13 10-27 11-11
DAVENPORT WFO 30 -09-23 27 -10-05 10-16 10-29 11-11
DECORAH-2-N 32 -08-30 28 -09-02 10-10 11-01 11-10
DENISON 29 -09-12 21 -09-21 10-18 11-02 11-11
Des Moines Airport 31 -09-22 26 -09-28 10-24 11-08 11-21
Donnellson 31 -09-20 25 -09-28 10-25 11-10 11-22
DUBUQUE-LOCK-AND-DAM 31 -09-20 24 -09-30 10-25 11-10 11-22
Eldora 31 -08-29 28 -09-22 10-17 11-02 11-11
Elkader 6SSW (Osborn) 32 -08-29 0 -09-02 10-09 10-27 11-10
Estherville 4E 32 -09-09 27 -09-18 10-07 10-27 11-06
FAIRFIELD 32 -09-11 28 -09-21 10-24 11-08 11-22
FAYETTE 32 -09-01 27 -09-12 10-10 10-28 11-10
FOREST-CITY 31 -09-01 27 -09-18 10-13 10-28 11-09
FORT-DODGE 32 -09-03 27 -09-13 10-17 11-02 11-10
Fort Madison 32 -09-22 26 -09-28 10-27 11-11 11-24
GREENFIELD 32 -09-17 27 -09-22 10-19 11-08 11-21
GRUNDY-CENTER 32 -09-12 28 -09-18 10-13 11-02 11-10
GUTHRIE-CENTER 31 -09-02 28 -09-19 10-17 11-02 11-11
GUTTENBERG-L-AND-D-10 32 -09-18 25 -09-28 10-24 11-06 11-21
HAMPTON-2-NW 32 -09-11 28 -09-12 10-12 11-01 11-10
HOLSTEIN 5 NNW 30 -10-02 28 -10-19 10-03 10-16 10-24
INDIANOLA-2-SSW 30 -09-15 28 -09-22 10-19 11-08 11-21
Iowa City 32 -09-14 28 -09-18 10-20 11-06 11-21
IOWA-FALLS 31 -08-30 28 -09-18 10-12 11-01 11-10
JEFFERSON 32 -08-29 28 -09-18 10-18 11-02 11-11
KEOSAUQUA 31 -09-11 28 -09-18 10-24 11-09 11-22
KNOXVILLE 31 -09-18 28 -09-26 10-24 11-08 11-21
LAKE PARK 30 -09-12 28 -09-15 10-12 10-28 11-08
Lamoni 32 -09-18 27 -09-28 10-24 11-08 11-21
Le Claire L&D 14 32 -09-26 28 -09-28 10-28 11-11 11-23
LEMARS 31 -09-11 28 -09-12 10-12 10-28 11-08
LITTLE SIOUX 2NW 31 -09-15 27 -09-23 10-12 10-25 11-10
LOGAN 30 -09-12 28 -09-13 10-17 11-02 11-11
LOWDEN 32 -09-13 26 -09-24 10-13 11-01 11-11
MANCHESTER-2 32 -09-13 27 -09-16 10-13 11-02 11-11
MAPLETON NO. 2 31 -09-11 27 -09-19 10-15 11-02 11-08
MAQUOKETA-2-W 31 -09-11 28 -09-23 10-17 11-03 11-12
MARSHALLTOWN 31 -09-12 28 -09-20 10-13 11-02 11-11
MASON-CITY 30 -08-30 28 -09-14 10-10 10-28 11-09
Milford 32 -09-03 28 -09-18 10-13 10-31 11-08
MOUNT-AYR 32 -09-13 28 -09-19 10-22 11-05 11-21
MOUNT-PLEASANT 32 -09-13 28 -09-24 10-24 11-10 11-22
MUSCATINE 29 -09-20 23 -09-28 10-24 11-10 11-21
MUSCATINE 2N 27 -10-02 27 -10-02 10-17 11-11 11-22
NEW-HAMPTON 28 -09-01 28 -09-01 10-13 11-01 11-10
NEWTON 32 -09-18 23 -09-28 10-23 11-06 11-21
NORTHWOOD 32 -09-13 28 -09-18 10-10 10-28 11-08
OAKLAND-2-E 32 -09-03 28 -09-22 10-17 11-03 11-11
OELWEIN 1E 32 -09-15 28 -10-05 10-13 10-29 11-11
OSAGE 30 -09-14 28 -09-18 10-13 11-01 11-10
OSCEOLA-3-WSW 31 -09-15 28 -09-22 10-19 11-07 11-21
OSKALOOSA 31 -09-13 27 -09-20 10-19 11-08 11-21
Ottumwa 32 -09-15 23 -09-28 10-24 11-09 11-22
PERRY 32 -09-12 27 -09-18 10-17 11-02 11-11
POCAHONTAS 31 -09-02 27 -09-18 10-12 10-28 11-10
Postville 32 -09-02 20 -09-21 10-17 11-02 11-11
PRIMGHAR 30 -09-12 25 -09-18 10-16 10-31 11-09
RATHBUN DAM 32 -09-22 28 -10-01 10-18 11-08 11-21
RED-OAK 32 -09-11 28 -09-22 10-19 11-03 11-21
ROCK-RAPIDS 31 -09-03 26 -09-10 10-07 10-24 11-05
ROCKWELL-CITY 32 -09-12 28 -09-18 10-17 11-01 11-10
SAC-CITY 32 -09-03 28 -09-20 10-17 11-01 11-11
SANBORN 32 -09-03 25 -09-18 10-10 10-27 11-07
SHENANDOAH-1-NE 32 -09-16 28 -09-20 10-24 11-07 11-21
SIBLEY-5-NNE 30 -08-20 23 -09-11 10-07 10-26 11-03
SIGOURNEY 32 -09-13 25 -09-21 10-19 11-08 11-21
SIOUX CENTER 2 SE 31 -09-03 24 -09-19 10-16 10-28 11-10
SIOUX CITY ANG 31 -09-23 20 -10-02 10-12 10-26 11-10
SIOUX-CITY-WSO-AP 30 -09-13 25 -09-22 10-17 11-02 11-10
SIOUX-RAPIDS 31 -09-03 28 -09-19 10-09 10-27 11-07
Spencer 31 -09-03 28 -09-15 10-09 10-27 11-08
SPIRIT LAKE 31 -09-12 28 -09-18 10-17 11-01 11-10
STANLEY 31 -09-13 26 -09-23 10-12 10-22 11-11
STORM-LAKE-2-E 32 -09-12 28 -09-18 10-17 11-02 11-10
SWEA CITY 4 W 32 -09-03 26 -09-22 10-09 10-29 11-10
TOLEDO 31 -09-11 27 -09-20 10-17 11-02 11-11
VINTON 32 -09-13 28 -09-21 10-18 11-03 11-12
WASHINGTON 30 -09-13 28 -09-23 10-24 11-08 11-21
WATERLOO 32 -09-11 28 -09-18 10-13 11-02 11-11
WAUKON 32 -09-16 25 -09-25 10-13 11-02 11-10
WEBSTER-CITY 30 -09-11 25 -09-18 10-12 10-28 11-10
WILLIAMSBURG 32 -09-11 28 -09-20 10-18 11-03 11-12
Iowa - Northwest Climate Division 32 -09-03 28 -09-19 10-12 10-28 11-08
Iowa - North Central Climate Division 32 -09-15 28 -09-18 10-13 11-01 11-10
Iowa - Northeast Climate Division 32 -09-13 28 -09-22 10-17 11-02 11-11
Iowa - West Central Climate Division 31 -09-12 28 -09-20 10-17 11-02 11-11
Iowa - Central Climate Division 32 -09-13 28 -09-22 10-17 11-02 11-12
Iowa - East Central Climate Division 32 -09-18 28 -09-26 10-19 11-05 11-21
Iowa - Southwest Climate Division 30 -09-18 26 -09-28 10-19 11-06 11-21
Iowa - South Central Climate Division 31 -09-19 25 -09-28 10-24 11-08 11-21
Iowa - Southeast Climate Division 32 -09-13 25 -09-28 10-24 11-08 11-22
Waterloo Area 32 -09-11 28 -09-18 10-13 11-02 11-11
Ames Area 31 -09-13 26 -09-21 10-17 11-02 11-11
Cedar Rapids Area 31 -09-15 28 -09-24 10-19 11-03 11-19
Dubuque Area 32 -09-15 28 -09-20 10-20 11-05 11-21
Des Moines Area 31 -09-22 26 -09-28 10-24 11-08 11-21
Humboldt Area 31 -09-13 28 -09-16 10-16 11-01 11-10
Oelwein Area 20 -09-05 20 -09-05 10-16 11-02 11-11
Spencer Area 31 -09-03 28 -09-15 10-09 10-27 11-08
Sioux City Area 30 -09-13 25 -09-22 10-17 11-02 11-10