St. Charles, MO Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for St. Charles, a city in St. Louis County, Missouri.
Today
89°F
Patchy Fog then Sunny
Patchy fog before 8am. Sunny, with a high near 89. South wind around 3 mph.
7-day forecast for St. Charles
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 89°F | Patchy Fog then Sunny | 3 mph S | 0% |
| Tonight | 70°F | Mostly Clear | 6 mph SE | 0% |
| Wednesday | 90°F | Mostly Sunny | 5 mph S | 13% |
| Wednesday Night | 72°F | Chance Showers And Thunderstorms | 7 mph S | 71% |
| Thursday | 86°F | Showers And Thunderstorms Likely | 6 mph S | 71% |
| Thursday Night | 70°F | Slight Chance Showers And Thunderstorms | 5 mph SE | 23% |
| Friday | 87°F | Slight Chance Showers And Thunderstorms then Partly Sunny | 3 mph SW | 23% |
| Friday Night | 71°F | Chance Showers And Thunderstorms | 3 mph S | 26% |
| Saturday | 89°F | Chance Showers And Thunderstorms then Mostly Sunny | 5 mph SW | 26% |
| Saturday Night | 74°F | Mostly Clear | 6 mph S | 6% |
| Sunday | 92°F | Sunny | 6 to 9 mph S | 5% |
| Sunday Night | 76°F | Mostly Clear | 8 mph S | 5% |
| Monday | 93°F | Sunny | 8 mph SW | 5% |
| Monday Night | 76°F | Slight Chance Showers And Thunderstorms | 8 mph SW | 17% |
Forecast source: National Weather Service (api.weather.gov) for St. Charles (38.796, -90.515). Updated through the day.
Growing snapshot for St. Charles
Last spring frost
Apr 8
First fall frost
Oct 29
Growing season
203 days
Hardiness zone
6b
More local growing data for St. Charles: nearby ZIP 63045 weather · frost dates · planting calendar · Missouri frost dates
Nearby towns & communities
Affton
Ballwin
Bel-Nor
Bel-Ridge
Bella Villa
Bellefontaine Neighbors
Bellerive Acres
Berkeley
Beverly Hills
Black Jack
Breckenridge Hills
Brentwood
Bridgeton
Calverton Park
Castle Point
Champ
Charlack
Chesterfield
Clarkson Valley
Clayton
Concord
Cool Valley
Country Club Hills
Country Life Acres
Crestwood
Creve Coeur
Crystal Lake Park
Dellwood
Des Peres
Edmundson
Climate data from the nearest NOAA station, St Charles Elm Pt, Mo (4.1 mi from St. Charles). Frost dates are 1991–2020 averages, not a forecast. Page updated Aug 4, 2026.