Ontonagon, MI Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Ontonagon, a village in Ontonagon County, Michigan.
Tonight
49°F
Mostly Cloudy
Mostly cloudy, with a low around 49. Southeast wind around 5 mph.
7-day forecast for Ontonagon
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Tonight | 49°F | Mostly Cloudy | 5 mph SE | 7% |
| Saturday | 66°F | Mostly Sunny | 5 to 10 mph E | 4% |
| Saturday Night | 50°F | Mostly Cloudy | 0 to 10 mph NE | 5% |
| Sunday | 63°F | Partly Sunny | 15 to 20 mph NE | 5% |
| Sunday Night | 46°F | Mostly Cloudy | 5 to 15 mph NE | 0% |
| Monday | 62°F | Mostly Sunny | 5 to 15 mph E | 0% |
| Monday Night | 44°F | Mostly Clear | 5 to 10 mph E | 0% |
| Tuesday | 63°F | Sunny | 5 to 10 mph E | 0% |
| Tuesday Night | 45°F | Mostly Clear | 5 to 10 mph E | 1% |
| Wednesday | 65°F | Sunny | 5 mph E | 2% |
| Wednesday Night | 49°F | Partly Cloudy | 5 mph SE | 2% |
| Thursday | 66°F | Mostly Sunny | 5 mph W | 2% |
| Thursday Night | 51°F | Partly Cloudy | 5 mph S | 5% |
| Friday | 68°F | Mostly Sunny | 5 mph NW | 5% |
Forecast source: National Weather Service (api.weather.gov) for Ontonagon (46.866, -89.312). Updated through the day.
Growing snapshot for Ontonagon
Last spring frost
May 27
First fall frost
Oct 1
Growing season
127 days
Hardiness zone
5a
More local growing data for Ontonagon: nearby ZIP 49953 weather · frost dates · planting calendar · Michigan frost dates
Nearby towns & communities
Climate data from the nearest NOAA station, Ontonagon 6 Se, Mi (10.9 mi from Ontonagon). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.