Frostline.info

Frost line depth in Iowa

Estimated frost depth in typical soil runs from 36″ to 50″ across Iowa's 99 counties. Pick your county or enter a ZIP code for a local estimate.

Deepest frost

  1. Dickinson County 50″
  2. Howard County 49″
  3. Emmet County 49″
  4. Winnebago County 49″
  5. Osceola County 49″

Mildest

  1. Lee County 36″
  2. Fremont County 36″
  3. Van Buren County 37″
  4. Ringgold County 37″
  5. Page County 37″

Frost depth by county

CountyEst. frost (typical soil)Typical code range
Adair County40″36–48″
Adams County41″36–54″
Allamakee County46″36–60″
Appanoose County38″30–48″
Audubon County42″36–54″
Benton County42″36–54″
Black Hawk County46″36–60″
Boone County44″36–54″
Bremer County46″36–60″
Buchanan County46″36–60″
Buena Vista County48″42–60″
Butler County46″36–60″
Calhoun County45″36–54″
Carroll County43″36–54″
Cass County41″36–54″
Cedar County42″36–54″
Cerro Gordo County48″42–60″
Cherokee County47″42–60″
Chickasaw County47″42–60″
Clarke County40″36–48″
Clay County48″42–60″
Clayton County44″36–54″
Clinton County42″36–54″
Crawford County43″36–54″
Dallas County42″36–54″
Davis County38″30–48″
Decatur County39″36–48″
Delaware County45″36–54″
Des Moines County38″30–48″
Dickinson County50″42–60″
Dubuque County43″36–54″
Emmet County49″42–60″
Fayette County46″36–60″
Floyd County47″42–60″
Franklin County46″36–60″
Fremont County36″30–48″
Greene County42″36–54″
Grundy County46″36–60″
Guthrie County42″36–54″
Hamilton County45″36–54″
Hancock County48″42–60″
Hardin County45″36–54″
Harrison County41″36–54″
Henry County38″30–48″
Howard County49″42–60″
Humboldt County47″42–60″
Ida County46″36–60″
Iowa County41″36–54″
Jackson County42″36–54″
Jasper County42″36–54″
Jefferson County38″30–48″
Johnson County40″36–48″
Jones County43″36–54″
Keokuk County40″36–48″
Kossuth County48″42–60″
Lee County36″30–48″
Linn County42″36–54″
Louisa County38″30–48″
Lucas County39″36–48″
Lyon County48″42–60″
Madison County41″36–54″
Mahaska County40″36–48″
Marion County39″36–48″
Marshall County44″36–54″
Mills County38″30–48″
Mitchell County48″42–60″
Monona County42″36–54″
Monroe County38″30–48″
Montgomery County39″36–48″
Muscatine County39″36–48″
O'Brien County48″42–60″
Osceola County49″42–60″
Page County37″30–48″
Palo Alto County48″42–60″
Plymouth County45″36–60″
Pocahontas County47″42–60″
Polk County42″36–54″
Pottawattamie County40″36–54″
Poweshiek County43″36–54″
Ringgold County37″30–48″
Sac County45″36–54″
Scott County39″36–48″
Shelby County41″36–54″
Sioux County47″42–60″
Story County43″36–54″
Tama County44″36–54″
Taylor County38″30–48″
Union County40″36–54″
Van Buren County37″30–48″
Wapello County39″30–48″
Warren County40″36–48″
Washington County39″30–48″
Wayne County40″36–48″
Webster County45″36–54″
Winnebago County49″42–60″
Winneshiek County48″42–60″
Woodbury County44″36–54″
Worth County48″42–60″
Wright County47″42–60″

Common questions

What is the frost line depth in Iowa?

It ranges from about 36 inches in the mildest county to 50 inches in the coldest, in typical soil.

Which Iowa county has the deepest frost?

Dickinson County, at about 50 inches in typical soil.