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 31 1902-09-13 27 1926-09-26 10-18 11-03 11-19
ALBIA 31 1991-09-19 25 1984-09-29 10-19 11-10 11-21
ALGONA 29 1893-09-02 27 1929-09-18 10-17 11-02 11-10
Allerton 31 1991-09-19 27 1984-09-29 10-18 11-05 11-21
ALLISON 30 1991-09-20 28 1984-09-26 10-18 11-03 11-12
AMES-8-WSW 31 1902-09-13 26 1918-09-21 10-18 11-02 11-12
ANAMOSA-1-WNW 29 1955-09-12 27 1956-09-20 10-10 10-29 11-12
ANKENY-3-S 32 1991-09-20 28 1984-09-26 10-18 11-04 11-20
ATLANTIC-1-NE 30 1893-09-02 28 1902-09-12 10-17 11-02 11-10
AUDUBON 30 1955-09-12 28 1962-09-20 10-10 11-02 11-10
BEDFORD-1-NNW 27 1991-09-19 27 1991-09-19 10-18 11-04 11-21
BELLE-PLAINE 32 1955-09-12 28 1991-09-20 10-17 11-03 11-20
BELLEVUE-L-AND-D-12 31 1956-09-20 25 1995-09-23 10-17 11-04 11-21
BLOOMFIELD 31 1991-09-20 25 1974-10-02 10-19 11-06 11-24
Boone 32 1975-09-12 28 1981-09-18 10-10 11-02 11-11
BRITT 31 2007-09-15 25 1983-09-22 10-09 10-28 11-10
Burlington 32 1991-09-20 26 2003-10-02 10-27 11-10 11-24
CARROLL-2-SSW 28 1974-09-03 28 1974-09-03 10-10 10-28 11-10
CASCADE 32 1955-09-11 28 1953-09-22 10-07 10-28 11-12
CASTANA-EXP-FARM 30 1991-09-19 28 1995-09-22 10-18 11-02 11-12
CEDAR-RAPIDS-1 32 2007-09-15 24 1926-09-26 10-20 11-05 11-21
CENTERVILLE 32 1991-09-19 27 1979-10-05 10-26 11-10 11-23
CHARITON 32 1955-09-12 28 1991-09-20 10-17 11-04 11-20
CHARLES-CITY 32 1955-09-12 28 1991-09-20 10-10 11-03 11-11
CHEROKEE 31 1974-09-03 27 1955-09-11 10-07 10-26 11-04
CLARINDA 31 1902-09-13 28 1918-09-21 10-19 11-03 11-19
CLARION 32 1974-09-03 25 1974-09-22 10-09 10-28 11-09
CLINTON-1 31 1902-09-13 28 1928-09-25 10-19 11-09 11-22
CORNING 32 1902-09-12 27 1983-09-21 10-17 11-02 11-20
CRESCO-1-NE 31 1975-09-13 27 1991-09-20 10-05 10-28 11-05
Creston 28 1991-09-19 28 1991-09-19 10-18 11-03 11-20
DECORAH-2-N 32 1915-08-30 28 1946-09-02 10-10 11-01 11-10
DENISON 29 1902-09-12 21 1918-09-21 10-18 11-02 11-11
Des Moines Airport 31 1995-09-22 26 1942-09-28 10-24 11-08 11-21
Donnellson 31 1991-09-20 27 1984-09-29 10-19 11-05 11-21
DUBUQUE-LOCK-AND-DAM 31 1956-09-20 24 1899-09-30 10-25 11-10 11-22
Eldora 32 1962-09-20 28 1974-09-22 10-10 11-03 11-10
Elkader 6SSW (Osborn) 28 2007-09-15 28 2007-09-15 09-27 10-16 10-28
Emmetsburg 32 2011-09-15 24 1995-09-22 10-10 11-02 11-10
ESTHERVILLE-2-N 30 2007-09-15 28 1991-09-20 10-07 10-28 11-05
FAIRFIELD 32 1917-09-11 28 1918-09-21 10-24 11-10 11-22
FAYETTE 32 1949-09-01 27 1902-09-12 10-10 10-28 11-10
FOREST-CITY 30 2011-09-15 26 1974-09-22 10-10 10-28 11-10
FORT-DODGE 32 1974-09-03 28 1974-09-22 10-16 11-02 11-11
Fort Madison 32 1983-09-23 27 1974-10-02 10-28 11-19 11-24
GLENWOOD 30 1902-09-12 28 1902-09-13 10-19 11-03 11-21
GREENFIELD 32 1981-09-17 28 1995-09-22 10-19 11-05 11-21
GRINNELL-3-SW 31 1976-09-10 27 1991-09-20 10-17 11-02 11-12
GRUNDY-CENTER 31 2007-09-15 27 1974-09-22 10-09 10-28 11-10
GUTHRIE-CENTER 31 1893-09-02 28 1991-09-19 10-17 11-02 11-11
GUTTENBERG-L-AND-D-10 32 1973-09-18 28 1984-09-29 10-19 11-06 11-21
HAMPTON-2-NW 32 1955-09-11 28 1955-09-12 10-12 11-02 11-10
HARLAN 29 1991-09-19 27 1951-09-28 10-16 11-02 11-11
HAWARDEN 31 1974-09-03 24 1991-09-19 10-09 10-28 11-04
Holstein 31 1991-09-20 28 1984-09-29 10-18 11-05 11-21
HUMBOLDT-2 31 2011-09-15 26 1974-09-22 10-10 11-02 11-10
INDEPENDENCE-2-W 32 1974-09-03 28 1975-09-13 10-10 10-29 11-10
INDIANOLA-2-SSW 30 1979-09-15 28 1979-09-22 10-19 11-08 11-21
IOWA-CITY 32 1923-09-14 28 1916-09-18 10-20 11-06 11-22
IOWA-FALLS 32 1976-09-10 26 1974-09-22 10-10 10-29 11-10
JEFFERSON 32 2011-09-15 23 1974-10-02 10-18 11-03 11-12
KEOSAUQUA 31 1917-09-11 28 1916-09-18 10-24 11-10 11-22
KNOXVILLE 31 1991-09-19 27 1974-10-02 10-19 11-07 11-21
Lamoni 32 1991-09-19 24 1974-10-02 10-19 11-05 11-21
Le Claire L&D 14 32 1984-09-29 25 1974-10-02 10-28 11-11 11-24
LEMARS 31 1955-09-11 28 1902-09-12 10-13 10-28 11-08
LOGAN 30 1902-09-12 28 1902-09-13 10-18 11-02 11-11
MANCHESTER-2 29 2007-09-15 27 1984-09-16 10-07 10-28 11-10
MAQUOKETA-2-W 31 1917-09-11 28 1983-09-23 10-17 11-03 11-13
MARSHALLTOWN 31 1955-09-12 28 1896-09-20 10-17 11-02 11-11
MASON-CITY 30 1915-08-30 28 1923-09-14 10-10 10-28 11-09
Milford 32 1974-09-03 27 1983-09-21 10-10 10-31 11-04
MOUNT-AYR 32 1902-09-13 28 1991-09-19 10-19 11-05 11-21
MOUNT-PLEASANT 29 1991-09-20 25 1974-10-02 10-19 11-10 11-24
MUSCATINE 29 1991-09-20 26 1984-09-29 10-25 11-10 11-24
NEW-HAMPTON 28 1949-09-01 28 1949-09-01 10-17 11-01 11-10
NEWTON 29 1974-09-22 27 1972-09-30 10-18 11-05 11-21
NORTHWOOD 31 1953-09-13 26 1974-09-22 10-10 10-28 11-08
OAKLAND-2-E 32 1974-09-03 28 1995-09-22 10-16 11-03 11-11
OELWEIN-2-S 28 1955-09-11 28 1955-09-11 10-10 11-02 11-10
ONAWA 30 1955-09-11 28 1991-09-19 10-19 11-02 11-11
OSAGE 32 2007-09-15 28 1974-09-22 10-15 11-02 11-11
OSCEOLA-3-WSW 31 2007-09-15 28 1974-09-22 10-18 11-04 11-20
OSKALOOSA 31 1902-09-13 27 1991-09-20 10-19 11-05 11-21
Ottumwa 32 2007-09-15 27 1984-09-29 10-24 11-10 11-23
PERRY 32 1955-09-12 28 1974-09-22 10-10 11-02 11-11
POCAHONTAS 30 2007-09-15 28 1983-09-20 10-07 10-28 11-07
PRIMGHAR 31 1984-09-15 27 1991-09-19 10-16 11-02 11-10
RED-OAK 32 1979-09-15 28 1995-09-22 10-18 11-03 11-20
ROCK-RAPIDS 31 1974-09-03 26 1894-09-10 10-07 10-24 11-04
ROCKWELL-CITY 32 1902-09-12 28 1929-09-18 10-17 11-01 11-10
SAC-CITY 32 1974-09-03 27 1974-09-22 10-10 11-02 11-11
Sheldon 32 1974-09-03 28 2007-09-15 10-07 10-26 11-04
SHENANDOAH-1-NE 30 1980-09-17 26 1983-09-23 10-19 11-05 11-21
SIBLEY-5-NNE 30 1974-09-03 23 1955-09-11 10-07 10-26 11-03
SIDNEY 30 1991-09-19 28 1995-09-22 10-19 11-08 11-23
SIGOURNEY 31 1995-09-22 28 1964-09-28 10-18 11-05 11-21
SIOUX-CITY-WSO-AP 32 2007-09-15 25 1995-09-22 10-15 11-02 11-10
SIOUX-RAPIDS 31 1974-09-03 28 1991-09-19 10-09 10-28 11-07
Spencer 31 1974-09-03 28 2007-09-15 10-09 10-27 11-04
STORM-LAKE-2-E 32 1902-09-12 28 1929-09-18 10-17 11-02 11-10
TIPTON 32 1902-09-13 28 1991-09-20 10-18 11-05 11-21
TOLEDO 31 2007-09-15 28 1962-09-20 10-10 10-29 11-12
TRIPOLI-4-N 31 2007-09-15 27 1974-09-22 10-10 11-02 11-12
VINTON 32 1953-09-13 28 1982-09-21 10-18 11-03 11-21
Wapello 31 1991-09-20 24 1942-09-28 10-25 11-10 11-22
WASHINGTON 30 1902-09-13 28 1983-09-23 10-24 11-08 11-22
WATERLOO 32 1917-09-11 28 1929-09-18 10-13 11-02 11-11
WAUKON 32 2011-09-16 27 1984-09-26 10-16 11-02 11-11
WEBSTER-CITY 30 1955-09-11 25 1929-09-18 10-12 10-28 11-10
WILLIAMSBURG 31 1955-09-12 28 1991-09-20 10-17 11-04 11-20
WINTERSET 31 1955-09-12 28 1962-09-20 10-18 11-03 11-20
Iowa - Northwest Climate Division 32 1974-09-03 28 1991-09-19 10-09 10-28 11-04
Iowa - North Central Climate Division 30 2011-09-15 26 1974-09-22 10-10 11-02 11-10
Iowa - Northeast Climate Division 32 2007-09-15 27 1974-09-22 10-10 11-03 11-11
Iowa - West Central Climate Division 29 1991-09-19 28 1995-09-22 10-17 11-02 11-11
Iowa - Central Climate Division 32 1991-09-19 27 1984-09-29 10-17 11-03 11-19
Iowa - East Central Climate Division 30 1991-09-20 28 1984-09-29 10-18 11-05 11-21
Iowa - Southwest Climate Division 29 1991-09-19 28 1995-09-22 10-18 11-03 11-20
Iowa - South Central Climate Division 31 1991-09-19 27 1984-09-29 10-18 11-05 11-21
Iowa - Southeast Climate Division 32 1991-09-20 26 1974-10-02 10-25 11-10 11-24