St. Clair, MI Weather & Growing Conditions
Overnight
53°F
Slight Chance Light Rain
A slight chance of rain. Mostly cloudy. Low around 53, with temperatures rising to around 55 overnight. East northeast wind around 5 mph. Chance of precipitation is 20%. New rainfall amounts less than a tenth of an inch possible.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Overnight | 53°F | Slight Chance Light Rain | 5 mph ENE | 23% |
| Saturday | 67°F | Chance Light Rain then Showers And Thunderstorms Likely | 3 to 7 mph ESE | 62% |
| Saturday Night | 54°F | Slight Chance Showers And Thunderstorms then Showers And Thunderstorms Likely | 3 to 7 mph E | 71% |
| Sunday | 66°F | Chance Rain Showers | 5 to 14 mph NNE | 40% |
| Sunday Night | 51°F | Slight Chance Rain Showers then Mostly Cloudy | 7 to 14 mph NE | 20% |
| Monday | 64°F | Mostly Cloudy | 9 to 13 mph NE | 5% |
| Monday Night | 48°F | Mostly Cloudy | 12 mph NE | 9% |
| Tuesday | 63°F | Mostly Cloudy then Slight Chance Rain Showers | 13 mph ENE | 18% |
| Tuesday Night | 50°F | Chance Rain Showers | 13 mph ENE | 46% |
| Wednesday | 62°F | Chance Rain Showers | 12 mph ENE | 51% |
| Wednesday Night | 51°F | Chance Showers And Thunderstorms | 5 to 9 mph ENE | 51% |
| Thursday | 65°F | Slight Chance Showers And Thunderstorms | 6 to 9 mph NE | 22% |
| Thursday Night | 51°F | Slight Chance Rain Showers then Mostly Cloudy | 3 to 7 mph NE | 15% |
| Friday | 68°F | Mostly Sunny | 3 to 9 mph NNE | 10% |
Forecast source: National Weather Service (api.weather.gov). Updated through the day.
Growing snapshot for St. Clair, MI
Last spring frost
Apr 19
First fall frost
Nov 3
Growing season
196 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, Port Huron, Mi (10.3 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.