NWS Chicago ILXH.W 0001June 30, 2026
Extreme Heat Warning: Winnebago, Boone, McHenry and 21 more, IL and IN
The National Weather Service office in Chicago issued an extreme heat warning for Winnebago, Boone, McHenry and 21 more in Illinois, Indiana, which was in force until 12:00 a.m. local time on July 3. It was the 1st extreme heat warning the NWS office in Chicago issued in 2026. Illinois had 5 extreme heat warnings in June 2026, against 1 in an average June of 2008-2025 (Illinois's extreme heat warnings by year).
ExpiredWarning
In force for 3 days; it has expired. The agency may have replaced it with a new notice.
The notice
- Issued by
- National Weather Service, Chicago IL
- Area
- Winnebago, Boone, McHenry and 21 more
- State
- Illinois
- Level
- Warning
- Issued
- 1:51 a.m. CDT, June 30, 2026
- Expires
- 12:00 a.m. CDT, July 3, 2026
- CAP severity, certainty, urgency
- Severe, Likely, Expected
- VTEC event
- KLOT XH.W 0001
- Official source
- National Weather Service: the notice at its source
Extreme Heat Warnings in Illinois since 2008Every warning type in Illinois
Source: National Weather Service: the notice at its source. AreaZine rebuilds this page from the agency's record; the agency's page is the one to act on. A U.S. Government work, in the public domain.
The notice as issued
* WHAT...Dangerously hot conditions with heat index values around 105 expected each afternoon. * WHERE...Portions of central, east central, north central, and northeast Illinois and northwest Indiana. * WHEN...Until midnight CDT /1 AM EDT/ Thursday Night. * IMPACTS...Heat related illnesses increase significantly during extreme heat and high humidity events. * ADDITIONAL DETAILS...Dangerous heat is now expected to persist through Thursday. Thunderstorms may begin to bring some relief from the heat for portions of northern Illinois by Thursday afternoon or evening.
What the agency told people to do
Drink plenty of fluids, stay in an air-conditioned room, stay out of the sun, and check up on relatives and neighbors. Do not leave young children and pets in unattended vehicles. Car interiors will reach lethal temperatures in a matter of minutes.
Source: National Weather Service: the notice at its source. The text is the agency's, unedited. A U.S. Government work, in the public domain.