Harman US

St. Clair, MI Weather & Growing Conditions

This Afternoon
67°F
Rain Showers Likely
Rain showers likely. Cloudy. High near 67, with temperatures falling to around 64 in the afternoon. East southeast wind around 7 mph. Chance of precipitation is 70%. New rainfall amounts less than a tenth of an inch possible.

7-day forecast

WhenTempForecastWindPrecip
This Afternoon 67°F Rain Showers Likely 7 mph ESE 71%
Tonight 56°F Showers And Thunderstorms Likely 3 to 7 mph ENE 85%
Sunday 68°F Patchy Fog then Mostly Cloudy 5 to 14 mph NNE 61%
Sunday Night 50°F Mostly Cloudy 7 to 14 mph NE 0%
Monday 64°F Partly Sunny 8 to 12 mph NE 0%
Monday Night 47°F Mostly Cloudy 7 to 10 mph NE 2%
Tuesday 64°F Partly Sunny 10 to 14 mph ENE 9%
Tuesday Night 50°F Chance Rain Showers 13 mph ENE 45%
Wednesday 63°F Chance Rain Showers 14 mph E 45%
Wednesday Night 50°F Chance Rain Showers 7 to 12 mph E 39%
Thursday 65°F Chance Rain Showers 9 mph E 26%
Thursday Night 49°F Partly Cloudy 3 to 7 mph ENE 11%
Friday 68°F Mostly Sunny 3 to 7 mph NE 11%
Friday Night 49°F Partly Cloudy 2 to 6 mph NNE 5%

Forecast source: National Weather Service (api.weather.gov). Updated through the day.

Growing snapshot for St. Clair, MI

Last spring frost
May 3
First fall frost
Oct 18
Growing season
167 days
Hardiness zone
6a

Explore more for St. Clair, MI: full frost dates · planting calendar · Michigan frost dates

Climate data from the nearest NOAA station, Algonac Wwtp, Mi (10.7 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.