Weldon Spring, MO Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Weldon Spring, a city in St. Charles County, Missouri.
Overnight
73°F
Mostly Clear
Mostly clear, with a low around 73. South wind around 3 mph.
7-day forecast for Weldon Spring
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Overnight | 73°F | Mostly Clear | 3 mph S | 3% |
| Saturday | 96°F | Partly Sunny | 3 to 7 mph SW | 5% |
| Saturday Night | 72°F | Partly Cloudy | 5 mph SW | 4% |
| Sunday | 90°F | Slight Chance Rain Showers then Slight Chance Showers And Thunderstorms | 2 to 6 mph W | 40% |
| Sunday Night | 66°F | Showers And Thunderstorms Likely | 7 mph N | 70% |
| Monday | 76°F | Showers And Thunderstorms Likely | 6 to 9 mph NE | 70% |
| Monday Night | 58°F | Chance Showers And Thunderstorms | 6 to 9 mph NE | 34% |
| Tuesday | 69°F | Slight Chance Rain Showers then Mostly Cloudy | 10 mph N | 20% |
| Tuesday Night | 53°F | Mostly Cloudy | 5 to 9 mph N | 3% |
| Wednesday | 72°F | Mostly Sunny | 7 mph N | 1% |
| Wednesday Night | 55°F | Partly Cloudy | 2 to 6 mph N | 0% |
| Thursday | 74°F | Mostly Sunny | 2 to 6 mph N | 2% |
| Thursday Night | 57°F | Partly Cloudy | 2 to 6 mph NE | 4% |
| Friday | 75°F | Partly Sunny | 2 to 6 mph NE | 8% |
Forecast source: National Weather Service (api.weather.gov) for Weldon Spring (38.709, -90.653). Updated through the day.
Growing snapshot for Weldon Spring
Last spring frost
Apr 10
First fall frost
Oct 26
Growing season
199 days
Hardiness zone
6b
More local growing data for Weldon Spring: nearby ZIP 63304 weather · frost dates · planting calendar · Missouri frost dates
Nearby towns & communities
Augusta
Cottleville
Dardenne Prairie
Defiance
Flint Hill
Foristell
Josephville
Lake St. Louis
New Melle
O'Fallon
St. Paul
St. Peters
Weldon Spring Heights
Wentzville
West Alton
Climate data from the nearest NOAA station, Weldon Spring Nws, Mo (0.5 mi from Weldon Spring). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.