St. Clair, MO Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for St. Clair, a city in Franklin County, Missouri.
This Afternoon
97°F
Sunny
Sunny, with a high near 97. Southwest wind around 3 mph.
7-day forecast for St. Clair
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| This Afternoon | 97°F | Sunny | 3 mph SW | 1% |
| Tonight | 70°F | Partly Cloudy | 3 mph SW | 1% |
| Sunday | 91°F | Mostly Sunny | 2 mph W | 9% |
| Sunday Night | 65°F | Chance Showers And Thunderstorms then Showers And Thunderstorms Likely | 2 mph NE | 65% |
| Monday | 79°F | Showers And Thunderstorms Likely | 5 mph NE | 67% |
| Monday Night | 58°F | Showers And Thunderstorms Likely | 5 mph N | 67% |
| Tuesday | 70°F | Mostly Cloudy | 6 mph N | 9% |
| Tuesday Night | 52°F | Mostly Cloudy | 5 mph N | 1% |
| Wednesday | 71°F | Mostly Sunny | 5 mph N | 0% |
| Wednesday Night | 51°F | Partly Cloudy | 2 mph N | 0% |
| Thursday | 74°F | Mostly Sunny | 2 mph N | 1% |
| Thursday Night | 55°F | Mostly Cloudy | 1 mph N | 8% |
| Friday | 77°F | Slight Chance Rain Showers | 0 to 3 mph NE | 22% |
| Friday Night | 56°F | Slight Chance Rain Showers then Mostly Cloudy | 2 mph NE | 22% |
Forecast source: National Weather Service (api.weather.gov) for St. Clair (38.347, -90.994). Updated through the day.
Growing snapshot for St. Clair
Last spring frost
Apr 11
First fall frost
Oct 23
Growing season
194 days
Hardiness zone
6b
More local growing data for St. Clair: nearby ZIP 63077 weather · frost dates · planting calendar · Missouri frost dates
Nearby towns & communities
Berger
Charmwood
Gerald
Gray Summit
LaBarque Creek
Lake St. Clair
Lake Tekakwitha
Leslie
Miramiguoa Park
New Haven
Oak Grove Village
Pacific
Parkway
Stanton
Sullivan
Three Creeks
Union
Villa Ridge
Washington
Climate data from the nearest NOAA station, Union, Mo (8 mi from St. Clair). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 20, 2026.