Weather Alerts For Ontonagon, MI

# HEADLINE -------------------- FROST ADVISORY IN EFFECT FROM 2 AM EDT /1 AM CDT/ TO 9 AM EDT /8 AM CDT/ WEDNESDAY # DETAILS -------------------- WHAT Temperatures as low as 32 will result in frost formation. WHERE Portions of central Upper and western Upper Michigan. WHEN From 2 AM EDT /1 AM CDT/ to 9 AM EDT /8 AM CDT/ Wednesday. IMPACTS Frost could harm sensitive outdoor vegetation. Sensitive outdoor plants may be killed if left uncovered. ISSUED AT Tuesday, September 22, 2026 at 1:23 PM EDT ISSUED BY National Weather Service Marquette MI HEADER URGENT - WEATHER MESSAGE # PRECAUTIONARY/PREPAREDNESS ACTIONS -------------------- Take steps now to protect tender plants from the cold. # AREAS AFFECTED -------------------- Southern Schoolcraft, Alger, Baraga, Delta, Dickinson, Gogebic, Iron, Luce, Marquette, Northern Schoolcraft, Ontonagon, Southern Houghton Including the cities of Sidnaw, Ontonagon, Gwinn, Newberry, Grand Marais, Iron Mountain, Manistique, Ironwood, Munising, Iron River, Seney, L'Anse, Kenton, Gladstone, Escanaba, and Marquette