Frost Dates in Iowa
The following chart is based on weather data collected from 1981 to 2010.* Probabilities indicate the likelihood of experiencing 32°F on or after the given date in spring and on or before the given date in fall.
Find your city or city closest to you to determine the likely date for the first freeze in fall and the last freeze in spring.
Cities and towns listed are grouped by their location in the state from north to south. Within each group, cities are listed from west to east.
Date of First Freeze in Fall and Last Freeze in Spring
Northern Iowa Cities | North-Central Iowa Cities | South-Central Iowa Cities | Southern Iowa Cities
Northern Iowa
| Location | Date of first 32°F freeze in 10% of years | Date of first 32°F freeze in 50% of years | Date of first 32°F freeze in 90% of years | Date of last 32°F freeze in 10% of years | Date of last 32°F freeze in 50% of years | Date of last 32°F freeze in 90% of years |
|---|---|---|---|---|---|---|
|
Sioux Center |
Sep. 19 |
Sep. 28 |
Oct. 8 |
Apr. 14 |
Apr. 28 |
May 14 |
|
Cherokee |
Sep. 19 |
Sep. 26 |
Oct. 10 |
Apr. 18 |
May 1 |
May 16 |
|
Spirit Lake |
Sep. 21 |
Oct. 3 |
Oct. 14 |
Apr. 8 |
Apr. 30 |
May 8 |
|
Mason City |
Sep. 20 |
Oct. 3 |
Oct. 10 |
Apr. 19 |
May 3 |
May 16 |
|
New Hampton |
Sep. 20 |
Oct. 2 |
Oct. 12 |
Apr. 10 |
Apr. 29 |
May 9 |
|
Fayette |
Sep. 18 |
Sep. 29 |
Oct. 11 |
Apr. 17 |
May 6 |
May 21 |
|
Decorah |
Sep. 21 |
Oct. 3 |
Oct. 13 |
Apr. 20 |
May 9 |
May 21 |
North-Central Iowa
| Location | Date of first 32°F freeze in 10% of years | Date of first 32°F freeze in 50% of years | Date of first 32°F freeze in 90% of years | Date of last 32°F freeze in 10% of years | Date of last 32°F freeze in 50% of years | Date of last 32°F freeze in 90% of years |
|---|---|---|---|---|---|---|
|
Sioux City |
Sep. 20 |
Sep. 29 |
Oct. 13 |
Apr. 10 |
Apr. 26 |
May 11 |
|
Onawa |
Sep. 20 |
Oct. 1 |
Oct. 14 |
Apr. 15 |
Apr. 28 |
May 10 |
|
Sac City |
Sep. 20 |
Oct. 4 |
Oct. 17 |
Apr. 10 |
Apr. 26 |
May 10 |
|
Carroll |
Sep. 18 |
Oct. 2 |
Oct. 10 |
Apr. 13 |
Apr. 27 |
May 10 |
|
Webster City |
Sep. 18 |
Sep. 29 |
Oct. 10 |
Apr. 19 |
May 4 |
May 16 |
|
Ames |
Sep. 23 |
Oct. 6 |
Oct. 21 |
Apr. 9 |
Apr. 20 |
May 6 |
|
Eldora |
Sep. 25 |
Oct. 5 |
Oct. 17 |
Apr. 10 |
Apr. 23 |
May 8 |
|
Waterloo |
Sep. 19 |
Sep. 29 |
Oct. 11 |
Apr. 15 |
Apr. 25 |
May 15 |
|
Cedar Rapids |
Sep. 22 |
Oct. 5 |
Oct. 16 |
Apr. 9 |
Apr. 22 |
May 6 |
|
Manchester |
Sep. 21 |
Sep. 30 |
Oct. 11 |
Apr. 18 |
May 2 |
May 14 |
|
Dubuque |
Sep. 22 |
Oct. 5 |
Oct. 21 |
Apr. 9 |
Apr. 24 |
May 7 |
South-Central Iowa
| Location | Date of first 32°F freeze in 10% of years | Date of first 32°F freeze in 50% of years | Date of first 32°F freeze in 90% of years | Date of last 32°F freeze in 10% of years | Date of last 32°F freeze in 50% of years | Date of last 32°F freeze in 90% of years |
|---|---|---|---|---|---|---|
|
Council Bluffs |
Sep. 23 |
Oct. 6 |
Oct. 24 |
Apr. 8 |
Apr. 22 |
May 7 |
|
Harlan |
Sep. 22 |
Oct. 5 |
Oct. 24 |
Apr. 10 |
Apr. 24 |
May 9 |
|
Greenfield |
Sep. 21 |
Oct. 6 |
Oct. 25 |
Apr. 9 |
Apr. 24 |
May 3 |
|
Des Moines |
Sep. 26 |
Oct. 10 |
Oct. 27 |
Apr. 5 |
Apr. 18 |
Apr. 30 |
|
Grinnell |
Sep. 16 |
Sep. 27 |
Oct. 10 |
Apr. 18 |
May 5 |
May 16 |
|
Sigourney |
Oct. 1 |
1Oct. 2 |
Oct. 28 |
Apr. 5 |
Apr. 19 |
May 4 |
|
Washington |
Sep. 22 |
Oct. 10 |
Oct. 21 |
Apr. 5 |
Apr. 17 |
May 5 |
|
Iowa City |
Sep. 29 |
Oct. 13 |
Oct. 23 |
Mar. 31 |
Apr. 17 |
May 4 |
|
Le Claire |
Oct. 3 |
Oct. 17 |
Nov. 2 |
28-Mar |
Apr. 13 |
Apr. 27 |
|
Clinton |
Sep. 22 |
Oct. 7 |
Oct. 19 |
Apr. 6 |
Apr. 19 |
May 6 |
Southern Iowa
| Location | Date of first 32°F freeze in 10% of years | Date of first 32°F freeze in 50% of years | Date of first 32°F freeze in 90% of years | Date of last 32°F freeze in 10% of years | Date of last 32°F freeze in 50% of years | Date of last 32°F freeze in 90% of years |
|---|---|---|---|---|---|---|
|
Red Oak |
Sep. 18 |
Oct. 4 |
Oct. 17 |
Apr. 10 |
Apr. 22 |
May 6 |
|
Beaconsfield |
Sep. 23 |
Oct. 5 |
Oct. 27 |
Apr. 9 |
Apr. 20 |
May 2 |
|
Chariton |
Sep. 20 |
Sep. 30 |
Oct. 14 |
Apr. 17 |
Apr. 30 |
May 17 |
|
Ottumwa |
Sep. 25 |
Oct. 7 |
Oct. 28 |
Apr. 3 |
Apr. 17 |
May 3 |
|
Keosauqua |
Sep. 21 |
Oct. 7 |
Oct. 21 |
Apr. 9 |
Apr. 18 |
May 3 |
|
Fairfield |
Sep. 22 |
Oct. 10 |
Oct. 25 |
Apr. 5 |
Apr. 17 |
May 4 |
|
Mount Pleasant |
Sep. 23 |
Oct. 11 |
Oct. 22 |
Apr. 5 |
Apr. 18 |
May 6 |
|
Fort Madison |
Sep. 30 |
Oct. 19 |
Nov. 6 |
30-Mar |
Apr. 8 |
Apr. 19 |
|
Burlington |
Oct. 3 |
Oct. 18 |
Nov. 4 |
30-Mar |
Apr. 14 |
May 1 |
More Information
* The data in this chart was provided by the Midwestern Regional Climate Center (MRCC).
View a Frost/Freeze Map
Interactive mapping tools that utilize temperatures from the last 30 years can be found from the MRCC Vegetation Impact Program.
Select the "Freeze Climatology" link in the menu located on the left side of the page to get 30-year averages for 32°F freezes and 28°F freezes.