Madison, Wis. – Drivers across southern Wisconsin and northeast Iowa should brace for dangerously low visibility this morning, as dense fog blankets the region through 9 a.m. CDT. Visibility in some areas could drop to just a quarter-mile, creating hazardous travel on rural highways and urban corridors alike.
According to the National Weather Service, Dense Fog Advisories are in effect for over a dozen counties, including Dane, Columbia, Iowa, Lafayette, and Green in Wisconsin, as well as Dubuque, Clayton, and Fayette in Iowa. Motorists are urged to slow down, use low-beam headlights, and maintain extra distance between vehicles.
In cities like Madison, Dubuque, Platteville, and Decorah, fog may linger past sunrise, especially in low-lying areas and near rivers. The advisory covers both I-90 and Highway 151, which may see sudden drops in visibility.
The fog follows a stretch of humid, stagnant air and light overnight winds—ideal conditions for thick, ground-level moisture to settle.
This advisory may expand eastward if fog continues to develop before sunrise. Morning commuters are urged to check conditions before heading out. Another update is expected by 9 a.m.
