Illinois, Missouri Dense Fog Advisory | Effective 05/09/2026 00:01

Headline: 
Dense Fog Advisory issued May 9 at 2:01AM CDT until May 9 at 8:00AM CDT by NWS St Louis MO
Event: 
Dense Fog Advisory
Urgency: 
Expected
Effective: 
May 9, 2026 - 12:01am
Expires: 
May 9, 2026 - 6:00am
Description: 
* WHAT...Visibility one quarter mile or less in dense fog. * WHERE...Portions of southwest and west central Illinois and east central and southeast Missouri. * WHEN...Until 8 AM CDT this morning. * IMPACTS...Low visibility could make driving conditions hazardous.
Instruction: 
If driving, slow down, use your headlights, and leave plenty of distance ahead of you.
Area Description: 
Greene; Macoupin; Adams; Brown; Pike; Calhoun; Jersey; Madison; St. Clair; Monroe; St. Charles; St. Louis; St. Louis City; Jefferson; St. Francois; Ste. Genevieve; Iron; Madison; Reynolds
Forcast Office: 
NWS St Louis MO
Sender: 
w-nws.webmaster@noaa.gov