National Weather Service United States Department of Commerce

A trough is expected to swing through tonight and bring a few light rain showers to parts of the area. A few flakes may mix in as well. Otherwise the pattern looks quiet into the weekend. No big warmup is expected, however.
Cool temperatures are expected this week, with overnight temperatures flirting with the freezing mark at times, which is only a little below normal for mid-April. The average date for the last 32 or colder temperature across most of southern Wisconsin is between April 21st and May 10th, based on the 30 year climatological record from 1980 to 2010. Hence despite the emergence of those Tulips, Crocus and Daffodils, it's best to hold off on planting any temperature sensitive outdoor plants at this time.