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Lake St. Clair, MO Weather & Growing Conditions

Local forecast, frost dates, hardiness zone and planting guidance for Lake St. Clair, a community in Franklin County, Missouri.

Tonight
70°F
Slight Chance Showers And Thunderstorms then Mostly Clear
A slight chance of showers and thunderstorms before 8pm. Mostly clear, with a low around 70. South wind 0 to 3 mph. Chance of precipitation is 20%.

7-day forecast for Lake St. Clair

WhenTempForecastWindPrecip
Tonight 70°F Slight Chance Showers And Thunderstorms then Mostly Clear 0 to 3 mph S 21%
Saturday 96°F Partly Sunny 5 mph SW 4%
Saturday Night 71°F Partly Cloudy 3 mph SW 2%
Sunday 92°F Mostly Sunny then Slight Chance Showers And Thunderstorms 3 mph W 17%
Sunday Night 65°F Chance Showers And Thunderstorms then Showers And Thunderstorms Likely 2 mph NE 67%
Monday 79°F Showers And Thunderstorms Likely 3 mph N 68%
Monday Night 58°F Showers And Thunderstorms Likely 3 mph N 68%
Tuesday 70°F Chance Rain Showers then Mostly Cloudy 6 mph N 25%
Tuesday Night 52°F Mostly Cloudy 1 to 6 mph N 5%
Wednesday 72°F Mostly Sunny 3 mph N 1%
Wednesday Night 52°F Partly Cloudy 2 mph N 1%
Thursday 74°F Mostly Sunny 2 mph N 3%
Thursday Night 55°F Partly Cloudy 1 mph NE 3%
Friday 74°F Mostly Sunny 3 mph NE 8%

Forecast source: National Weather Service (api.weather.gov) for Lake St. Clair (38.323, -90.999). Updated through the day.

Growing snapshot for Lake St. Clair

Last spring frost
Apr 11
First fall frost
Oct 23
Growing season
194 days
Hardiness zone
6b

More local growing data for Lake St. Clair: nearby ZIP 63077 weather · frost dates · planting calendar · Missouri frost dates

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Climate data from the nearest NOAA station, Union, Mo (8 mi from Lake St. Clair). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.