Ontonagon, MI Weather & Growing Conditions
Today
67°F
Mostly Cloudy then Slight Chance Rain Showers
A slight chance of rain showers between 3pm and 4pm. Mostly cloudy. High near 67, with temperatures falling to around 63 in the afternoon. East wind around 5 mph. Chance of precipitation is 20%.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 67°F | Mostly Cloudy then Slight Chance Rain Showers | 5 mph E | 16% |
| Tonight | 49°F | Mostly Cloudy then Slight Chance Rain Showers | 0 to 5 mph N | 15% |
| Sunday | 63°F | Slight Chance Rain Showers then Partly Sunny | 10 to 15 mph NE | 22% |
| Sunday Night | 43°F | Mostly Cloudy | 0 to 15 mph E | 0% |
| Monday | 64°F | Partly Sunny | 0 to 10 mph E | 0% |
| Monday Night | 39°F | Mostly Clear | 0 to 10 mph E | 0% |
| Tuesday | 66°F | Sunny | 0 to 10 mph E | 0% |
| Tuesday Night | 41°F | Mostly Clear | 0 to 10 mph E | 0% |
| Wednesday | 69°F | Sunny | 0 to 5 mph E | 0% |
| Wednesday Night | 44°F | Mostly Clear | 0 to 5 mph SE | 1% |
| Thursday | 70°F | Sunny | 0 to 5 mph SE | 1% |
| Thursday Night | 47°F | Mostly Clear | 0 to 5 mph SE | 3% |
| Friday | 72°F | Mostly Sunny | 0 to 5 mph N | 2% |
| Friday Night | 49°F | Partly Cloudy | 5 mph SE | 3% |
Forecast source: National Weather Service (api.weather.gov). Updated through the day.
Growing snapshot for Ontonagon, MI
Last spring frost
May 27
First fall frost
Oct 1
Growing season
127 days
Hardiness zone
5a
Explore more for Ontonagon, MI: full frost dates · planting calendar · Michigan frost dates
Climate data from the nearest NOAA station, Ontonagon 6 Se, Mi (10.9 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.