Freeze Warnings and Frost Advisories in effect for tonight Temperatures to drop below freezing in Grand Rapids WXMI and last updated 2021-05-07 16:20:26-04 WEST MICHIGAN â Temperatures are to drop to around or below freezing for all of us overnight tonight. For this reason, the National Weather Service has issued Freeze Warnings ( purple shaded counties ) and Frost Advisories ( baby blue shaded counties ) across West Michigan for the hours of 2 A.M. to 9 A.M. Saturday. WXMI Common temperatures will drop to between 28-32 degrees in the counties outlined with a Freeze Warning. Common temperatures will drop to between 32-36 degrees in the counties outlined with a Frost Advisory.