Illinois mosquito forecast, by town

A daily mosquito bite-risk score for all 1294 Illinois towns, grouped by their 102 counties. Mosquito pressure is local, so pick your town for today's number, a 7-day outlook, and what's driving it.

Adams County · 14 towns

Alexander County · 5 towns

Bond County · 8 towns

Boone County · 5 towns

Brown County · 4 towns

Bureau County · 23 towns

Calhoun County · 5 towns

Carroll County · 7 towns

Cass County · 5 towns

Champaign County · 23 towns

Christian County · 13 towns

Clark County · 4 towns

Clay County · 6 towns

Clinton County · 14 towns

Coles County · 6 towns

Cook County · 119 towns

Crawford County · 6 towns

Cumberland County · 4 towns

De Witt County · 7 towns

DeKalb County · 12 towns

Douglas County · 8 towns

DuPage County · 30 towns

Edgar County · 8 towns

Edwards County · 4 towns

Effingham County · 10 towns

Fayette County · 7 towns

Ford County · 9 towns

Franklin County · 14 towns

Fulton County · 20 towns

Gallatin County · 7 towns

Greene County · 9 towns

Grundy County · 12 towns

Hamilton County · 5 towns

Hancock County · 15 towns

Hardin County · 3 towns

Henderson County · 8 towns

Henry County · 14 towns

Iroquois County · 21 towns

Jackson County · 11 towns

Jasper County · 7 towns

Jefferson County · 9 towns

Jersey County · 6 towns

Jo Daviess County · 10 towns

Johnson County · 7 towns

Kane County · 23 towns

Kankakee County · 19 towns

Kendall County · 8 towns

Knox County · 14 towns

Lake County · 46 towns

LaSalle County · 24 towns

Lawrence County · 5 towns

Lee County · 12 towns

Livingston County · 14 towns

Logan County · 10 towns

Macon County · 12 towns

Macoupin County · 27 towns

Madison County · 27 towns

Marion County · 13 towns

Marshall County · 8 towns

Mason County · 9 towns

Massac County · 3 towns

McDonough County · 10 towns

McHenry County · 27 towns

McLean County · 21 towns

Menard County · 5 towns

Mercer County · 10 towns

Monroe County · 6 towns

Montgomery County · 20 towns

Morgan County · 10 towns

Moultrie County · 6 towns

Ogle County · 13 towns

Peoria County · 15 towns

Perry County · 6 towns

Piatt County · 8 towns

Pike County · 17 towns

Pope County · 2 towns

Pulaski County · 7 towns

Putnam County · 6 towns

Randolph County · 14 towns

Richland County · 5 towns

Rock Island County · 15 towns

Saline County · 6 towns

Sangamon County · 25 towns

Schuyler County · 4 towns

Scott County · 7 towns

Shelby County · 11 towns

St. Clair County · 25 towns

Stark County · 4 towns

Stephenson County · 11 towns

Tazewell County · 16 towns

Union County · 6 towns

Vermilion County · 21 towns

Wabash County · 4 towns

Warren County · 5 towns

Washington County · 12 towns

Wayne County · 9 towns

White County · 10 towns

Whiteside County · 11 towns

Will County · 25 towns

Williamson County · 15 towns

Winnebago County · 11 towns

Woodford County · 15 towns

Illinois mosquito questions

What kinds of mosquitoes live in Illinois?
Illinois has floodwater mosquitoes (the dominant summer nuisance biter, which surges after heavy rain), the Asian tiger mosquito (a daytime biter that breeds in yard containers), the house mosquito (the main West Nile carrier), and swamp and cattail-marsh mosquitoes tied to the EEE cycle. Which ones dominate a given town depends on its local breeding habitat.
When does mosquito season start and end in Illinois?
In Illinois, mosquito numbers build from about mid-June, peak in mid-to-late summer, and fade with the first cool nights of fall. Biting largely stops once temperatures drop below about 50°F, and a hard freeze ends the season.
Is West Nile or EEE a risk in Illinois?
Both West Nile virus and Eastern equine encephalitis occur in the region, but human cases are rare. West Nile risk peaks in late-summer heat and tracks the house mosquito in developed areas; EEE rises after mid-July in swampy areas. For confirmed local activity, check the Illinois health department's arbovirus surveillance.
How do I keep mosquitoes out of my yard in Illinois?
The single biggest thing you control is standing water: empty anything that holds it, keep gutters clear, and change bird baths weekly. Use EPA-registered repellent at dawn and dusk, and for heavy biting a licensed mosquito-control service can treat breeding sites and resting spots you can't reach.