Saint Louis County

Extreme Heat Warning issued August 11 at 2:17AM CDT until August 12 at 8:00PM CDT by NWS St Louis MO

* WHAT...Dangerously hot conditions with heat index values up to 111. * WHERE...Portions of south central and southwest Illinois and central and east central Missouri. * WHEN...Until 8 PM CDT Wednesday. * IMPACTS...Heat related illnesses increase significantly during extreme heat and high humidity events.