Frostline.info

Frost line depth in Illinois

Estimated frost depth in typical soil runs from 22″ to 44″ across Illinois's 102 counties. Pick your county or enter a ZIP code for a local estimate.

Deepest frost

  1. Carroll County 44″
  2. Stephenson County 44″
  3. Jo Daviess County 43″
  4. Ogle County 42″
  5. Winnebago County 42″

Mildest

  1. Massac County 22″
  2. Pulaski County 22″
  3. Alexander County 22″
  4. Pope County 24″
  5. Hardin County 24″

Frost depth by county

CountyEst. frost (typical soil)Typical code range
Adams County34″30–42″
Alexander County22″18–30″
Bond County31″24–42″
Boone County41″36–54″
Brown County35″30–42″
Bureau County40″36–48″
Calhoun County32″30–42″
Carroll County44″36–54″
Cass County35″30–48″
Champaign County36″30–48″
Christian County33″30–42″
Clark County33″30–42″
Clay County31″24–42″
Clinton County30″24–42″
Coles County33″30–42″
Cook County37″30–48″
Crawford County31″30–42″
Cumberland County34″30–42″
De Witt County34″30–42″
DeKalb County40″36–54″
Douglas County34″30–42″
DuPage County39″30–48″
Edgar County33″30–42″
Edwards County29″24–36″
Effingham County34″30–42″
Fayette County32″30–42″
Ford County38″30–48″
Franklin County28″24–36″
Fulton County37″30–48″
Gallatin County26″24–36″
Greene County32″30–42″
Grundy County37″30–48″
Hamilton County29″24–36″
Hancock County35″30–42″
Hardin County24″18–30″
Henderson County37″30–48″
Henry County40″36–54″
Iroquois County38″30–48″
Jackson County27″24–36″
Jasper County34″30–42″
Jefferson County29″24–36″
Jersey County33″30–42″
Jo Daviess County43″36–54″
Johnson County24″24–30″
Kane County40″36–48″
Kankakee County38″30–48″
Kendall County39″36–48″
Knox County40″36–48″
Lake County41″36–54″
LaSalle County38″30–48″
Lawrence County31″24–42″
Lee County41″36–54″
Livingston County37″30–48″
Logan County34″30–42″
Macon County33″30–42″
Macoupin County31″30–42″
Madison County31″24–42″
Marion County31″24–42″
Marshall County39″30–48″
Mason County36″30–48″
Massac County22″18–30″
McDonough County36″30–48″
McHenry County41″36–54″
McLean County37″30–48″
Menard County35″30–42″
Mercer County38″30–48″
Monroe County28″24–36″
Montgomery County31″24–42″
Morgan County35″30–42″
Moultrie County33″30–42″
Ogle County42″36–54″
Peoria County39″36–48″
Perry County27″24–36″
Piatt County34″30–42″
Pike County33″30–42″
Pope County24″18–30″
Pulaski County22″18–30″
Putnam County39″30–48″
Randolph County26″24–36″
Richland County30″24–42″
Rock Island County39″36–48″
Saline County25″24–30″
Sangamon County34″30–42″
Schuyler County35″30–42″
Scott County34″30–42″
Shelby County33″30–42″
St. Clair County29″24–36″
Stark County41″36–54″
Stephenson County44″36–54″
Tazewell County37″30–48″
Union County24″24–30″
Vermilion County35″30–42″
Wabash County30″24–36″
Warren County37″30–48″
Washington County29″24–36″
Wayne County29″24–36″
White County29″24–36″
Whiteside County41″36–54″
Will County39″36–48″
Williamson County27″24–36″
Winnebago County42″36–54″
Woodford County39″30–48″

Common questions

What is the frost line depth in Illinois?

It ranges from about 22 inches in the mildest county to 44 inches in the coldest, in typical soil.

Which Illinois county has the deepest frost?

Carroll County, at about 44 inches in typical soil.