Montana, Wyoming Moderate Dense Fog Advisory | Effective 09/21/2026 03:57

Headline: 
Dense Fog Advisory issued September 21 at 4:57AM MDT until September 21 at 10:00AM MDT by NWS Billings MT
Event: 
Dense Fog Advisory
Urgency: 
Expected
Effective: 
September 21, 2026 - 3:57am
Expires: 
September 21, 2026 - 9:00am
Description: 
* WHAT...Areas of dense fog producing visibility one quarter mile or less. * WHERE...Portions of central, south central, and southeast Montana and north central Wyoming. * WHEN...Until 10 AM MDT this morning. * IMPACTS...Morning travelers can expect to encounter areas of very poor visibility. This includes portions of Interstate 90 from Big Timber to Billings, Hardin and Sheridan. Portions of Interstate 94, US-191, and US-212 will also be impacted. Please use caution and allow extra time for your morning commute. * ADDITIONAL DETAILS...Fog will slowly dissipate in the mid to late morning.
Instruction: 
If driving, slow down, use your low beam headlights, and leave plenty of distance ahead of you.
Area Description: 
Musselshell; Treasure; Northern Stillwater; Golden Valley; Northern Big Horn; Southern Rosebud; Judith Gap; Southern Big Horn; Northern Sweet Grass; Northern Carbon; Melville Foothills; Northeastern Yellowstone; Southern Wheatland; Southwestern Yellowstone; Sheridan Foothills
Forcast Office: 
NWS Billings MT
Sender: 
w-nws.webmaster@noaa.gov