Harman US

Ontonagon, MI Weather & Growing Conditions

This Afternoon
68°F
Mostly Cloudy
Mostly cloudy, with a high near 68. East wind around 5 mph.

7-day forecast

WhenTempForecastWindPrecip
This Afternoon 68°F Mostly Cloudy 5 mph E 7%
Tonight 50°F Mostly Cloudy then Slight Chance Rain Showers 0 to 5 mph N 19%
Sunday 60°F Slight Chance Rain Showers then Partly Sunny 5 to 15 mph NE 18%
Sunday Night 44°F Mostly Cloudy 5 to 15 mph E 1%
Monday 63°F Partly Sunny 0 to 10 mph E 0%
Monday Night 40°F Partly Cloudy 0 to 10 mph E 0%
Tuesday 65°F Sunny 0 to 10 mph E 0%
Tuesday Night 42°F Mostly Clear 0 to 10 mph E 0%
Wednesday 68°F Sunny 0 to 5 mph E 0%
Wednesday Night 46°F Mostly Clear 5 mph SE 0%
Thursday 70°F Sunny 0 to 5 mph E 2%
Thursday Night 49°F Partly Cloudy 0 to 5 mph SE 3%
Friday 72°F Mostly Sunny 0 to 5 mph W 3%
Friday Night 51°F Partly Cloudy 0 to 5 mph SE 1%

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.