Frost Dates in Iowa

Below is the likelihood of experiencing 32°F on or before the given date in fall and on or after the given date in spring.

Oak with frost on leavesLinks to high-population counties are below, and all counties are listed alphabetically.   
Early = only 10% of all freeze dates occurred before this day.
Average = the average freeze date for this location.
Late = only 10% of all freeze dates occured after this day.

This information is based on weather data collected from 1950-2021.*


Date of First Freeze in Fall  |  Date of Last Freeze in Spring


Quick Links to Populus Counties

Polk County First Fall Freeze Last Spring Freeze Des Moines, West Des Moines, Ankeny, Urbandale, Johnston, Altoona, Clive
Linn County First Fall Freeze Last Spring Freeze Cedar Rapids, Marion
Scott County First Fall Freeze Last Spring Freeze Davenport, Bettendorf
Johnson County First Fall Freeze Last Spring Freeze Iowa City, Coralville, North Liberty
Black Hawk County First Fall Freeze Last Spring Freeze Waterloo, Cedar Falls
Woodbury County First Fall Freeze Last Spring Freeze Sioux City
Dallas County First Fall Freeze Last Spring Freeze Waukee, West Des Moines, Urbandale, Clive, Grimes
Dubuque County First Fall Freeze Last Spring Freeze Dubuque
Story County First Fall Freeze Last Spring Freeze Ames
Pottawattamie County First Fall Freeze Last Spring Freeze Council Bluffs
Warren County First Fall Freeze Last Spring Freeze Indianola, Norwalk
Clinton County First Fall Freeze Last Spring Freeze Clinton
Muscatine County First Fall Freeze Last Spring Freeze Muscatine
Cerro Gordo County First Fall Freeze Last Spring Freeze Mason City
Marshall County First Fall Freeze Last Spring Freeze Marshalltown

Date of First Freeze in Fall

Listed alphabetically by county. 
Early = only 10% of all freeze dates occurred before this day.
Average = the average freeze date for this location.
Late = only 10% of all freeze dates occurred after this day.

County

Early First Fall Freeze (32°F)

Average First Fall Freeze (32°F)

Late First Fall Freeze (32°F)

Adair

Sep 26

Oct 07

Oct 23

Adams

Sep 26

Oct 08

Oct 25

Allamakee

Sep 26

Oct 07

Oct 21

Appanoose

Sep 30

Oct 14

Oct 28

Audubon

Sep 21

Oct 03

Oct 15

Benton

Sep 22

Oct 05

Oct 17

Black Hawk

Sep 22

Oct 05

Oct 18

Boone

Sep 23

Oct 06

Oct 20

Bremer

Sep 22

Oct 05

Oct 19

Buchanan

Sep 20

Oct 03

Oct 14

County

Early First Fall Freeze (32°F)

Average First Fall Freeze (32°F)

Late First Fall Freeze (32°F)

Buena Vista

Sep 23

Oct 06

Oct 23

Butler

Sep 27

Oct 07

Oct 22

Calhoun

Sep 27

Oct 07

Oct 20

Carroll

Sep 21

Oct 03

Oct 19

Cass

Sep 21

Oct 05

Oct 18

Cedar

Sep 24

Oct 09

Oct 22

Cerro Gordo

Sep 22

Oct 05

Oct 19

Cherokee

Sep 19

Oct 02

Oct 15

Chickasaw

Sep 22

Oct 05

Oct 18

Clarke

Sep 26

Oct 10

Oct 25

County

Early First Fall Freeze (32°F)

Average First Fall Freeze (32°F)

Late First Fall Freeze (32°F)

Clay

Sep 22

Oct 05

Oct 18

Clayton

Sep 21

Oct 03

Oct 15

Clinton

Oct 01

Oct 14

Oct 28

Crawford

Sep 23

Oct 06

Oct 20

Dallas

Sep 22

Oct 06

Oct 18

Davis

Oct 01

Oct 15

Oct 28

Decatur

Sep 29

Oct 12

Oct 29

Delaware

Sep 21

Oct 03

Oct 14

Des Moines

Oct 03

Oct 19

Nov 03

Dickinson

Sep 22

Oct 04

Oct 19

County

Early First Fall Freeze (32°F)

Average First Fall Freeze (32°F)

Late First Fall Freeze (32°F)

Dubuque

Sep 26

Oct 09

Oct 22

Emmet

Sep 22

Oct 04

Oct 20

Fayette

Sep 20

Oct 02

Oct 15

Floyd

Sep 27

Oct 07

Oct 21

Franklin

Sep 21

Oct 05

Oct 19

Fremont

Sep 30

Oct 13

Oct 27

Greene

Sep 24

Oct 06

Oct 21

Grundy

Sep 23

Oct 06

Oct 20

Guthrie

Sep 21

Oct 04

Oct 16

Hamilton

Sep 21

Oct 05

Oct 16

County

Early First Fall Freeze (32°F)

Average First Fall Freeze (32°F)

Late First Fall Freeze (32°F)

Hancock

Sep 22

Oct 05

Oct 18

Hardin

Sep 23

Oct 06

Oct 19

Harrison

Sep 26

Apr 16

Oct 20

Henry

Oct 01

Oct 15

Oct 29

Howard

Sep 20

Oct 02

Oct 13

Humboldt

Sep 23

Oct 07

Oct 23

Ida

Sep 21

Oct 04

Oct 15

Iowa

Sep 23

Oct 07

Oct 19

Jackson

Sep 27

Oct 09

Oct 22

Jasper

Sep 26

Oct 09

Oct 25

County

Early First Fall Freeze (32°F)

Average First Fall Freeze (32°F)

Late First Fall Freeze (32°F)

Jefferson

Sep 30

Oct 13

Oct 28

Johnson

Sep 27

Oct 09

Oct 22

Jones

Sep 22

Oct 05

Oct 17

Keokuk

Sep 30

Oct 13

Oct 28

Kossuth

Sep 25

Oct 06

Oct 18

Lee

Oct 06

Oct 19

Nov 02

Linn

Sep 25

Oct 06

Oct 18

Louisa

Oct 01

Oct 14

Oct 28

Lucas

Sep 27

Oct 08

Oct 21

Lyon

Sep 19

Sep 30

Oct 14

County

Early First Fall Freeze (32°F)

Average First Fall Freeze (32°F)

Late First Fall Freeze (32°F)

Madison

Sep 23

Oct 07

Oct 21

Mahaska

Sep 27

Oct 11

Oct 27

Marion

Sep 29

Oct 11

Oct 28

Marshall

Sep 26

Oct 08

Oct 21

Mills

Sep 28

Oct 10

Oct 27

Mitchell

Sep 23

Oct 06

Oct 19

Monona

Sep 26

Oct 07

Oct 22

Monroe

Sep 30

Oct 14

Oct 28

Montgomery

Sep 23

Oct 08

Oct 24

Muscatine

Sep 30

Oct 14

Oct 28

County

Early First Fall Freeze (32°F)

Average First Fall Freeze (32°F)

Late First Fall Freeze (32°F)

O'Brien

Sep 22

Oct 04

Oct 16

Osceola

Sep 21

Oct 03

Oct 15

Page

Sep 27

Oct 09

Oct 26

Palo Alto

Sep 25

Oct 07

Oct 23

Plymouth

Sep 20

Oct 02

Oct 16

Pocahontas

Sep 23

Oct 06

Oct 20

Polk

Sep 26

Oct 10

Oct 26

Pottawattamie

Sep 26

Oct 08

Oct 26

Poweshiek

Sep 25

Oct 07

Oct 21

Ringgold

Sep 27

Oct 11

Oct 27

County

Early First Fall Freeze (32°F)

Average First Fall Freeze (32°F)

Late First Fall Freeze (32°F)

Sac

Sep 24

Oct 07

Oct 24

Scott

Oct 05

Oct 19

Nov 02

Shelby

Sep 22

Oct 06

Oct 18

Sioux

Sep 19

Oct 01

Oct 14

Story

Sep 26

Oct 07

Oct 21

Tama

Sep 22

Oct 08

Oct 18

Taylor

Sep 27

Oct 10

Oct 27

Union

Sep 27

Oct 10

Oct 28

Van Buren

Oct 01

Oct 15

Oct 28

Wapello

Oct 01

Oct 15

Oct 28

County

Early First Fall Freeze (32°F)

Average First Fall Freeze (32°F)

Late First Fall Freeze (32°F)

Warren

Sep 27

Oct 10

Oct 23

Washington

Sep 28

Oct 12

Oct 27

Wayne

Sep 30

Oct 12

Oct 27

Webster

Sep 23

Oct 07

Oct 20

Winnebago

Sep 22

Oct 04

Oct 15

Winneshiek

Sep 21

Oct 03

Oct 15

Woodbury

Sep 21

Oct 04

Oct 16

Worth

Sep 23

Oct 05

Oct 18

Wright

Sep 21

Oct 03

Oct 15

County

Early First Fall Freeze (32°F)

Average First Fall Freeze (32°F)

Late First Fall Freeze (32°F)

Date of Last Freeze in Spring

Listed alphabetically by county. 
Early = only 10% of all freeze dates occurred before this day.
Average = the average freeze date for this location.
Late = only 10% of all freeze dates occurred after this day.

County

Early Last Spring Freeze Date (32°F)

Average Last Spring Freeze Date (32°F)

Late Last Spring Freeze Date (32°F)

Adair

Apr 11

Apr 25

May 10

Adams

Apr 11

Apr 24

May 08

Allamakee

Apr 09

Apr 26

May 11

Appanoose

Apr 05

Apr 17

May 03

Audubon

Apr 13

Apr 27

May 11

Benton

Apr 13

Apr 25

May 08

Black Hawk

Apr 14

Apr 28

May 11

Boone

Apr 13

Apr 26

May 08

Bremer

Apr 13

Apr 28

May 11

Buchanan

Apr 16

Apr 29

May 14

County

Early Last Spring Freeze Date (32°F)

Average Last Spring Freeze Date (32°F)

Late Last Spring Freeze Date (32°F)

Buena Vista

Apr 12

Apr 28

May 11

Butler

Apr 13

Apr 27

May 10

Calhoun

Apr 13

Apr 26

May 08

Carroll

Apr 13

Apr 27

May 09

Cass

Apr 11

Apr 26

May 11

Cedar

Apr 09

Apr 23

May 06

Cerro Gordo

Apr 15

Apr 29

May 11

Cherokee

Apr 16

May 01

May 14

Chickasaw

Apr 16

Apr 29

May 11

Clarke

Apr 09

Apr 23

May 08

County

Early Last Spring Freeze Date (32°F)

Average Last Spring Freeze Date (32°F)

Late Last Spring Freeze Date (32°F)

Clay

Apr 12

Apr 28

May 11

Clayton

Apr 16

Apr 29

May 12

Clinton

Apr 06

Apr 18

May 02

Crawford

Apr 09

Apr 25

May 09

Dallas

Apr 10

Apr 25

May 08

Davis

Apr 03

Apr 15

Apr 29

Decatur

Apr 07

Apr 20

May 03

Delaware

Apr 16

May 01

May 15

Des Moines

Apr 03

Apr 15

Apr 28

Dickinson

Apr 14

Apr 28

May 10

County

Early Last Spring Freeze Date (32°F)

Average Last Spring Freeze Date (32°F)

Late Last Spring Freeze Date (32°F)

Dubuque

Apr 10

Apr 23

May 06

Emmet

Apr 15

Apr 28

May 10

Fayette

Apr 18

May 01

May 15

Floyd

Apr 13

Apr 27

May 10

Franklin

Apr 17

Apr 28

May 11

Fremont

Apr 05

Apr 17

Apr 30

Greene

Apr 13

Apr 26

May 09

Grundy

Apr 16

Apr 27

May 10

Guthrie

Apr 13

Apr 27

May 09

Hamilton

Apr 13

Apr 29

May 13

County

Early Last Spring Freeze Date (32°F)

Average Last Spring Freeze Date (32°F)

Late Last Spring Freeze Date (32°F)

Hancock

Apr 14

Apr 28

May 11

Hardin

Apr 13

Apr 26

May 09

Harrison

Apr 11

Apr 24

May 07

Henry

Apr 05

Apr 17

Apr 30

Howard

Apr 21

May 03

May 15

Humboldt

Apr 11

Apr 27

May 09

Ida

Apr 14

Apr 29

May 12

Iowa

Apr 10

Apr 24

May 06

Jackson

Apr 10

Apr 25

May 08

Jasper

Apr 09

Apr 22

May 05

County

Early Last Spring Freeze Date (32°F)

Average Last Spring Freeze Date (32°F)

Late Last Spring Freeze Date (32°F)

Jefferson

Apr 05

Apr 17

May 01

Johnson

Apr 09

Apr 22

May 06

Jones

Apr 16

Apr 29

May 13

Keokuk

Apr 07

Apr 19

May 03

Kossuth

Apr 14

Apr 28

May 11

Lee

Apr 04

Apr 13

Apr 25

Linn

Apr 14

Apr 26

May 09

Louisa

Apr 05

Apr 17

May 02

Lucas

Apr 10

Apr 24

May 07

Lyon

Apr 18

May 01

May 14

County

Early Last Spring Freeze Date (32°F)

Average Last Spring Freeze Date (32°F)

Late Last Spring Freeze Date (32°F)

Madison

Apr 10

Apr 25

May 09

Mahaska

Apr 08

Apr 20

May 03

Marion

Apr 06

Apr 20

May 03

Marshall

Apr 13

Apr 24

May 08

Mills

Apr 08

Apr 22

May 08

Mitchell

Apr 16

Apr 30

May 11

Monona

Apr 09

Apr 26

May 10

Monroe

Apr 06

Apr 19

May 03

Montgomery

Apr 09

Apr 24

May 09

Muscatine

Apr 05

Apr 17

Apr 30

County

Early Last Spring Freeze Date (32°F)

Average Last Spring Freeze Date (32°F)

Late Last Spring Freeze Date (32°F)

O'Brien

Apr 15

Apr 29

May 14

Osceola

Apr 17

Apr 30

May 14

Page

Apr 08

Apr 22

May 06

Palo Alto

Apr 14

Apr 27

May 10

Plymouth

Apr 15

Apr 28

May 12

Pocahontas

Apr 10

Apr 26

May 09

Polk

Apr 09

Apr 22

May 04

Pottawattamie

Apr 09

Apr 24

May 08

Poweshiek

Apr 13

Apr 26

May 09

Ringgold

Apr 08

Apr 21

May 06

County

Early Last Spring Freeze Date (32°F)

Average Last Spring Freeze Date (32°F)

Late Last Spring Freeze Date (32°F)

Sac

Apr 09

Apr 26

May 09

Scott

Apr 05

Apr 15

Apr 30

Shelby

Apr 09

Apr 24

May 09

Sioux

Apr 18

May 01

May 13

Story

Apr 13

Apr 24

May 06

Tama

Apr 14

Apr 27

May 10

Taylor

Apr 09

Apr 22

May 06

Union

Apr 09

Apr 23

May 07

Van Buren

Apr 05

Apr 18

May 01

Wapello

Apr 05

Apr 16

Apr 30

County

Early Last Spring Freeze Date (32°F)

Average Last Spring Freeze Date (32°F)

Late Last Spring Freeze Date (32°F)

Warren

Apr 09

Apr 23

May 06

Washington

Apr 07

Apr 20

May 04

Wayne

Apr 07

Apr 20

May 03

Webster

Apr 13

Apr 26

May 09

Winnebago

Apr 14

Apr 28

May 10

Winneshiek

Apr 18

May 02

May 18

Woodbury

Apr 09

Apr 26

May 10

Worth

Apr 17

Apr 28

May 11

Wright

Apr 14

Apr 29

May 25

County

Early Last Spring Freeze Date (32°F)

Average Last Spring Freeze Date (32°F)

Late Last Spring Freeze Date (32°F)


More Information

* This data was provided by the Midwestern Regional Climate Center (MRCC).  Visit that website to get more detailed information and statistics.