Alert archive / Illinois / Extreme Heat Warnings
Extreme Heat Warnings in Illinois, 2026
18 extreme heat warnings in 2026. 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 extreme heat warnings reaches back to 2005.
Extreme Heat Warnings by county
Each county as a circle sized by its count in 2026. Tap one for its archive.
- Extreme Heat Warnings
- 18
- Busiest month
- July6 extreme heat warnings
- Busiest day
- July 26, 20263 extreme heat warnings
Over time
By month
The alerts
Every alert, in the order issued. Times are local, Central Time. Each opens its own page with the text, the map, the radar and the sounding.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 27, 1:15 PM CDT | Extreme Heat Warning | LSX | Adams, Bond, Brown, Calhoun, Clinton, Fayette and 11 more | 7 days |
| Jun 27, 1:24 PM CDT | Extreme Heat Warning | DVN | Bureau, Carroll, Hancock, Henderson, Henry, Jo Daviess and 7 more | 6 days |
| Jun 28, 11:18 AM CDT | Extreme Heat Warning | LOT | Boone, Cook, DeKalb, DuPage, Ford, Grundy and 12 more | 5 days |
| Jun 28, 11:28 AM CDT | Extreme Heat Warning | PAH | Alexander, Edwards, Franklin, Gallatin, Hamilton, Hardin and 13 more | 5 days |
| Jun 30, 12:23 AM CDT | Extreme Heat Warning | ILX | Cass, Champaign, Christian, Clark, Clay, Coles and 29 more | 4 days |
| Jul 20, 8:38 AM CDT | Extreme Heat Warning | PAH | Alexander, Franklin, Gallatin, Hamilton, Hardin, Jackson and 10 more | 34 hr |
| Jul 25, 2:49 AM CDT | Extreme Heat Warning | DVN | Bureau, Carroll, Hancock, Henderson, Henry, Jo Daviess and 7 more | 67 hr |
| Jul 25, 11:30 PM CDT | Extreme Heat Warning | PAH | Alexander, Edwards, Franklin, Gallatin, Hamilton, Hardin and 13 more | 68 hr |
| Jul 26, 12:23 AM CDT | Extreme Heat Warning | ILX | Cass, Champaign, Christian, Clark, Clay, Coles and 29 more | 45 hr |
| Jul 26, 12:40 AM CDT | Extreme Heat Warning | LSX | Adams, Bond, Brown, Calhoun, Clinton, Fayette and 11 more | 66 hr |
| Jul 27, 2:10 AM CDT | Extreme Heat Warning | LOT | Boone, DeKalb, Ford, Grundy, Iroquois, Kane and 9 more | 19 hr |
| Aug 9, 1:05 AM CDT | Extreme Heat Warning | LSX | Clinton, Madison, Marion, Monroe, Randolph, Saint Clair and 1 more | 8 days |
| Aug 10, 12:50 AM CDT | Extreme Heat Warning | PAH | Alexander, Edwards, Franklin, Gallatin, Hamilton, Hardin and 13 more | 7 days |
| Sep 1, 11:46 AM CDT | Extreme Heat Warning | PAH | Alexander, Edwards, Franklin, Gallatin, Hamilton, Hardin and 13 more | 4 days |
| Sep 2, 2:02 AM CDT | Extreme Heat Warning | DVN | Bureau, Hancock, Henderson, Henry, McDonough, Mercer and 3 more | 4 days |
| Sep 2, 11:14 AM CDT | Extreme Heat Warning | ILX | Cass, Champaign, Christian, Clark, Clay, Coles and 29 more | 3 days |
| Sep 3, 12:12 AM CDT | Extreme Heat Warning | LSX | Adams, Bond, Brown, Calhoun, Clinton, Fayette and 11 more | 68 hr |
| Sep 3, 1:08 AM CDT | Extreme Heat Warning | LOT | Cook | 13 hr |
By county
Every county with at least one alert. A county page lists each alert that covered it.
- Alexander County5
- Franklin County5
- Gallatin County5
- Hamilton County5
- Hardin County5
- Jackson County5
- Jefferson County5
- Johnson County5
- Massac County5
- Perry County5
- Pope County5
- Pulaski County5
- Saline County5
- Union County5
- White County5
- Williamson County5
- Clinton County4
- Madison County4
- Marion County4
- Monroe County4
- Randolph County4
- Saint Clair County4
- Washington County4
- Edwards County4
- Wabash County4
- Wayne County4
- Adams County3
- Bond County3
- Brown County3
- Calhoun County3
- Fayette County3
- Greene County3
- Jersey County3
- Macoupin County3
- Montgomery County3
- Pike County3
- Bureau County3
- Hancock County3
- Henderson County3
- Henry County3
62 more counties
- McDonough County3
- Mercer County3
- Putnam County3
- Rock Island County3
- Warren County3
- Cass County3
- Champaign County3
- Christian County3
- Clark County3
- Clay County3
- Coles County3
- Crawford County3
- Cumberland County3
- DeWitt County3
- Douglas County3
- Edgar County3
- Effingham County3
- Fulton County3
- Jasper County3
- Knox County3
- Lawrence County3
- Logan County3
- McLean County3
- Macon County3
- Marshall County3
- Mason County3
- Menard County3
- Morgan County3
- Moultrie County3
- Peoria County3
- Piatt County3
- Richland County3
- Sangamon County3
- Schuyler County3
- Scott County3
- Shelby County3
- Stark County3
- Tazewell County3
- Vermilion County3
- Woodford County3
- Carroll County2
- Jo Daviess County2
- Stephenson County2
- Whiteside County2
- Boone County2
- Cook County2
- DeKalb County2
- Ford County2
- Grundy County2
- Iroquois County2
- Kane County2
- Kankakee County2
- Kendall County2
- LaSalle County2
- Lee County2
- Livingston County2
- McHenry County2
- Ogle County2
- Will County2
- Winnebago County2
- DuPage County1
- Lake County1
The busiest days
Days with the most alerts issued, by UTC date.
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. Warning verification from the Mesonet's Cow. Rebuilt daily.