Frost Chances Overnight Threaten Growing Season
Now is the time to protect sensitive plants.
MADISON, Wis. (WMTV) -What a difference a day makes across southern Wisconsin! From late season warmth in the 70s on Wednesday to the coldest air of the season spilling in Thursday night. The seasons first widespread 30 degree temperatures and frost will threaten the growing season as we wrap up the week. This has prompted a First Alert Day here at NBC15 as we prepare for the colder temperatures.
A Frost Advisory has been issued for all of southern Wisconsin late Thursday night into early Friday morning. Overnight lows are expected to dip down into the middle and upper 20s to the north and the lower and middle 30s to the south. Widespread frost is anticipated across the area with localized areas experiencing a killing freeze.
You may be wondering how frost can form in areas that don’t officially fall below 32 degrees. The answer lies in in the fact that the official temperature is measured several feet off the ground. Right at ground level early in the morning, the temperature can run a few degrees cooler. That will put most places at or below the freezing mark and lead to widespread frost formation.
Ideal frost formation requires light winds, clear skies, and temperatures below 37 degrees. The wild card tonight will be some lingering cloud cover, especially south of Madison. Should some clouds linger a littler longer, temperatures may be a touch warmer near the stateline.
While widespread frost is likely into Friday morning, a widespread freeze is anticipated into early Saturday morning. This will likely end the growing season for the rest of Wisconsin and has prompted another First Alert Day through early Saturday. It is that time of year where colder temperatures become more and more likely and a reminder that keeping that ice scraper in your car might be a good idea.
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