An "unseasonably cold air mass" is settling over the area, warns the National Weather Service, and it could result in areas of frost after midnight and into Monday morning.
A frost advisory is in effect from 2 a.m. to 8 a.m. Monday. Temperatures will fall into the 30s tonight across the majority of southeastern Michigan as a clearing sky and light wind combine with the cold air, and "areas of frost (are) possible well after midnight."
Temperatures will still be in the low 40s at the bus stop, too, so don't forget to bundle up the kids before you send them off to school.
The National Weather Service also warns that sensitive vegetation could be damaged or killed if left uncovered tonight.