Frost advisories issued across much of Michigan; Metro Detroit to see low 40s
The first cool day of October is giving way to a frosty night across Michigan, with no warm-up expected for the weekend.
The National Weather Service has issued frost advisories for a large swath of the state, from Sault Ste. Marie in the Upper Peninsula's eastern tip to Jackson in the southern lower half, as temperatures dip into the 30s overnight.
A frost advisory is in effect from midnight through 8 a.m. Friday for the following counties and areas: Emmet, Cheboygan, Presque Isle, Antrim, Otsego, Montmorency, Alpena, Grand Traverse, Kalkaska, Crawford, Oscoda, Alcona, Manistee, Wexford, Missaukee, Roscommon, Ogemaw, Iosco, Gladwin, Arenac, western central and southeast Chippewa, western/eastern Mackinac and Charlevoix.
From 2 a.m. through 9 a.m. Friday, a frost advisory covers Lake, Osceola, Clare, Newaygo, Mecosta, Isabella, Montcalm, Gratiot, Kent, Ionia, Clinton, Barry, Eaton, Ingham, Kalamazoo, Calhoun and Jackson counties.
"Frost could kill sensitive outdoor vegetation if left uncovered," the weather service said.
In Metro Detroit, the mercury is expected to fall into the low 40s as skies become mostly cloudy.
Parts of the region saw light showers Thursday as the high at Detroit Metro Airport reached 63, about five degrees below average for Oct. 1.
The thermometer isn't forecast to rise above the mid-50s Friday or Saturday.
Similar readings are on tap for Sunday, when more showers could return. Monday should hover around 60.
Historically, the final four months of the year in Detroit all see double-digit drops in average temperatures compared to the previous month. The average high in October, 61.6, is more than 13 degrees lower than the average high for September, 74.
September 2020 fell short of that, with its average high reaching only 73.2, weather service records show. The month was rainier than normal, with 3.95 inches versus 3.27 historically.
Though there were eight days last month when temperatures topped 80, they never passed 85.
There were also three days with temperatures below 45 degrees, including Sept. 19, which tied a record low, 38, set in 1982.