St. Charles, MO Weather & Growing Conditions
This Afternoon
97°F
Partly Sunny
Partly sunny, with a high near 97. Heat index values as high as 100. Southwest wind around 7 mph.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| This Afternoon | 97°F | Partly Sunny | 7 mph SW | 1% |
| Tonight | 73°F | Partly Cloudy | 6 mph SW | 1% |
| Sunday | 92°F | Partly Sunny then Chance Showers And Thunderstorms | 2 to 8 mph W | 32% |
| Sunday Night | 67°F | Chance Showers And Thunderstorms then Showers And Thunderstorms Likely | 6 to 10 mph N | 73% |
| Monday | 79°F | Showers And Thunderstorms Likely | 9 mph NE | 73% |
| Monday Night | 60°F | Chance Showers And Thunderstorms | 6 to 10 mph NE | 47% |
| Tuesday | 72°F | Slight Chance Rain Showers then Mostly Cloudy | 9 to 13 mph N | 24% |
| Tuesday Night | 55°F | Mostly Cloudy | 6 to 13 mph N | 1% |
| Wednesday | 73°F | Partly Sunny | 9 mph N | 0% |
| Wednesday Night | 55°F | Partly Cloudy | 2 to 9 mph N | 0% |
| Thursday | 76°F | Mostly Sunny | 2 to 7 mph N | 1% |
| Thursday Night | 59°F | Mostly Cloudy then Slight Chance Rain Showers | 2 to 7 mph NE | 15% |
| Friday | 79°F | Slight Chance Rain Showers | 2 to 7 mph NE | 19% |
| Friday Night | 60°F | Slight Chance Rain Showers then Mostly Cloudy | 6 mph NE | 19% |
Forecast source: National Weather Service (api.weather.gov). Updated through the day.
Growing snapshot for St. Charles, MO
Last spring frost
Apr 8
First fall frost
Oct 29
Growing season
203 days
Hardiness zone
6b
Explore more for St. Charles, MO: full frost dates · planting calendar · Missouri frost dates
Climate data from the nearest NOAA station, St Charles Elm Pt, Mo (4.1 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 20, 2026.