Illinois extreme heat warnings
There are no extreme heat warnings in Illinois right now. The last one was issued on September 3, 2026.
Dangerous, potentially deadly heat is expected. Stay cool and check on vulnerable people.
Updated from the National Weather Service · lists refresh hourly; the live map loads current alerts directly from the NWS
Active extreme heat warnings in Illinois
None right now. Other active alerts in Illinois: none.
Extreme Heat Warnings in Illinois by year
Illinois averaged 5.9 extreme heat warnings per year from 2016 to 2025, and has had 18 so far in 2026. The most recent was issued on September 3, 2026.
Counties with the most extreme heat warnings
What a extreme heat warning means
An extreme heat warning (formerly the excessive heat warning) is the highest heat alert. It is issued when the heat index or air temperature reaches dangerous levels, often for several days, with little relief overnight.
More about extreme heat warnings and the national map →
What to do
- Stay in air conditioning as much as possible.
- Check on older relatives and neighbors at least twice a day.
- Reschedule outdoor work to early morning.
More Illinois alerts
- Tornado Warnings
- Tornado Watches
- Severe Thunderstorm Warnings
- Flash Flood Warnings
- Flood Warnings
- Flood Watches
- Winter Storm Warnings
- Winter Storm Watches
- Winter Weather Advisories
- Cold Weather Advisories
- Freeze Warnings
- Frost Advisories
- Heat Advisories
- High Wind Warnings
- Wind Advisories
- Red Flag Warnings
- Dense Fog Advisories
- All Illinois alerts