Frost likely next two nights
Sunshine made for a beautiful Saturday and Sunday looks very similar, but all of that clear sky and a relatively light wind at night will allow temperatures to get a little chilly. A frost advisory has been issued for Sunday morning from 2:00 AM to 8:00 AM for all of southeast Wisconsin.
Low temperatures by Sunday morning will reach the middle 30s with some spots nearing freezing. Go ahead and cover or bring inside any plants especially sensitive plants.
The National Weather Service is already expecting to have to issue another frost advisory for Monday morning when temperatures could be even colder. Widespread low 30s will be possible by Monday morning with a freeze likely for some inland communities.
This is right around the time of year where we typically see our last average frost and freezes. At least on average, by the middle of May it's much safer to start planting.