Weather
Upper Peninsula Frost Risk Lasts Through 9 A.M.
Upper Peninsula Frost Risk Lasts Through 9 A.M.
By Cameron Hayes · 2026-09-21T20:00:46.847Z
Marquette, Michigan – Temperatures could fall to 33 degrees early Tuesday across much of the Upper Peninsula, bringing frost that could kill sensitive plants.
According to the National Weather Service in Marquette, a frost advisory takes effect at 2 a.m. EDT Tuesday and continues until 9 a.m. EDT. In areas observing Central time, the advisory runs from 1 a.m. to 8 a.m.
The advisory covers Alger, Delta, Dickinson, Luce, Marquette, Northern Schoolcraft, Southern Schoolcraft, Gogebic and Ontonagon counties.
Communities within the advisory include Marquette, Munising, Escanaba, Gladstone, Iron Mountain, Ironwood, Ontonagon, Newberry, Grand Marais, Gwinn, Manistique and Seney.
Temperatures as low as 33 degrees will allow frost to form during the early morning. Sensitive outdoor vegetation could be damaged, and tender plants may be killed if they remain uncovered.
Residents across the affected Upper Peninsula counties should protect gardens, flowers and other vulnerable vegetation before temperatures reach their lowest levels. The National Weather Service advises residents to take steps now to protect tender plants from the cold.
Timing varies by time zone. The frost threat begins at 2 a.m. Tuesday in Eastern time areas and 1 a.m. in Central time areas, continuing through the early morning.
The advisory expires at 9 a.m. EDT, or 8 a.m. CDT, Tuesday. Residents should keep sensitive vegetation protected through that time as temperatures near 33 degrees support frost formation.