Iowa frost dates by county and ZIP code
Across 970 Iowa ZIP codes the average last spring frost runs Apr 8 to May 8 and the average first fall frost Sep 28 to Oct 29 (50% odds, 32°F, NOAA 1991–2020 normals), with USDA hardiness zones. Download the table as CSV.
Counties
- Adair
- Adams
- Allamakee
- Appanoose
- Audubon
- Benton
- Black Hawk
- Boone
- Bremer
- Buchanan
- Buena Vista
- Butler
- Calhoun
- Carroll
- Cass
- Cedar
- Cerro Gordo
- Cherokee
- Chickasaw
- Clarke
- Clay
- Clayton
- Clinton
- Crawford
- Dallas
- Davis
- Decatur
- Delaware
- Des Moines
- Dickinson
- Dubuque
- Emmet
- Fayette
- Floyd
- Franklin
- Fremont
- Greene
- Grundy
- Guthrie
- Hamilton
- Hancock
- Hardin
- Harrison
- Henry
- Howard
- Humboldt
- Ida
- Iowa
- Jackson
- Jasper
- Jefferson
- Johnson
- Jones
- Keokuk
- Kossuth
- Lee
- Linn
- Louisa
- Lucas
- Lyon
- Madison
- Mahaska
- Marion
- Marshall
- Mills
- Mitchell
- Monona
- Monroe
- Montgomery
- Muscatine
- O'Brien
- Osceola
- Page
- Palo Alto
- Plymouth
- Pocahontas
- Polk
- Pottawattamie
- Poweshiek
- Ringgold
- Sac
- Scott
- Shelby
- Sioux
- Story
- Tama
- Taylor
- Union
- Van Buren
- Wapello
- Warren
- Washington
- Wayne
- Webster
- Winnebago
- Winneshiek
- Woodbury
- Worth
- Wright
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