Madison, WI – Residents across much of Wisconsin should prepare for a cold start to the week as a Frost Advisory takes effect from 2 a.m. to 8 a.m. CDT Monday, Oct. 20, according to multiple National Weather Service offices.
The advisory spans central, southern, and northeastern Wisconsin, including the Madison, Green Bay, Fond du Lac, Wisconsin Rapids, and La Crosse regions. Overnight temperatures are forecast to dip into the low 30s, with some areas seeing readings as cold as 31°F, leading to widespread frost formation.
According to the National Weather Service in La Crosse, Milwaukee/Sullivan, and Green Bay, the frost could harm or kill sensitive outdoor vegetation if not properly covered. Residents are advised to bring plants indoors or use coverings to protect gardens and crops.
Counties under the advisory include Adams, Juneau, Dane, Columbia, Dodge, Jefferson, Fond du Lac, Rock, Walworth, Sauk, Marquette, Green Lake, Waupaca, Outagamie, Brown, Winnebago, and Calumet, among others.
This early-season frost signals the arrival of colder fall conditions following a stretch of mild October weather. Temperatures are expected to rebound into the 50s and 60s by afternoon Monday.
