Excessive Heat Warnings in Illinois
98 excessive heat warnings since 1986. An alert counts here when it covered any part of the state, so the counties below add up to more than the state. The archive of excessive heat warnings reaches back to 2005.
Excessive Heat Warnings by county
Each county as a circle sized by its count since 1986. Tap one for its archive.
- Excessive Heat Warnings
- 98
- Busiest year
- 201012 excessive heat warnings
- Average year
- 6over 17 years on file
Over time
By year
Before late 2005 the archive holds only tornado, severe thunderstorm, flash flood and marine warnings, and from 1997 SPC's watches, so the jump that year is the archive widening, not the weather.
By month of the year
By county
Every county with at least one alert. A county page lists each alert that covered it.
- Madison County29
- Saint Clair County29
- Monroe County25
- Jackson County21
- Williamson County21
- Randolph County20
- Washington County20
- Franklin County20
- Perry County20
- Union County20
- Clinton County19
- Marion County19
- Alexander County19
- Gallatin County19
- Jefferson County19
- Johnson County19
- Massac County19
- Pulaski County19
- Saline County19
- Bond County18
- Fayette County18
- Jersey County18
- Hamilton County18
- White County18
- Calhoun County17
- Edwards County17
- Hardin County17
- Pope County17
- Rock Island County17
- Wabash County17
- Wayne County17
- Greene County16
- Macoupin County16
- Montgomery County16
- Cass County16
- Hancock County16
- Henderson County16
- Henry County16
- Logan County16
- McDonough County16
62 more counties
- Menard County16
- Mercer County16
- Morgan County16
- Sangamon County16
- Scott County16
- Warren County16
- Clay County15
- Crawford County15
- Effingham County15
- Jasper County15
- Lawrence County15
- Macon County15
- Richland County15
- Schuyler County15
- Pike County14
- Christian County14
- Cumberland County14
- Fulton County14
- Mason County14
- Moultrie County14
- Shelby County14
- Bureau County14
- Putnam County14
- Clark County13
- Coles County13
- Knox County13
- Peoria County13
- Stark County13
- Adams County12
- Brown County12
- Champaign County12
- DeWitt County12
- Douglas County12
- Edgar County12
- Piatt County12
- Tazewell County12
- Vermilion County12
- Whiteside County12
- Marshall County11
- Woodford County11
- Ford County10
- Iroquois County10
- Livingston County10
- McLean County10
- Carroll County10
- Jo Daviess County10
- Stephenson County10
- Grundy County9
- Kankakee County9
- LaSalle County9
- Lee County9
- DeKalb County8
- DuPage County8
- Kane County8
- Kendall County8
- Ogle County8
- Boone County7
- Lake County7
- McHenry County7
- Winnebago County7
- Will County4
- Cook County3
Nearby
Sources
National Weather Service watches, warnings, advisories and statements from the Iowa Environmental Mesonet's VTEC archive, which reconstructs tornado, severe thunderstorm, flash flood and marine warnings back to 1986 from the NWS text archive. Storm Prediction Center watches and mesoscale discussions from SPC's archive through the Mesonet. County centers from the US Census Bureau. Rebuilt daily.