West Alton, MO Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for West Alton, a city in St. Charles County, Missouri.
This Afternoon
98°F
Chance Showers And Thunderstorms
A chance of showers and thunderstorms. Sunny, with a high near 98. Heat index values as high as 106. Southeast wind around 5 mph. Chance of precipitation is 30%.
7-day forecast for West Alton
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| This Afternoon | 98°F | Chance Showers And Thunderstorms | 5 mph SE | 26% |
| Tonight | 73°F | Slight Chance Showers And Thunderstorms then Mostly Clear | 6 mph SE | 23% |
| Saturday | 99°F | Mostly Sunny | 3 to 9 mph SW | 6% |
| Saturday Night | 73°F | Partly Cloudy | 6 mph SW | 4% |
| Sunday | 94°F | Chance Rain Showers then Chance Showers And Thunderstorms | 3 to 8 mph W | 27% |
| Sunday Night | 67°F | Chance Showers And Thunderstorms then Showers And Thunderstorms Likely | 6 to 9 mph N | 64% |
| Monday | 81°F | Showers And Thunderstorms Likely | 7 to 13 mph N | 70% |
| Monday Night | 60°F | Showers And Thunderstorms Likely then Slight Chance Showers And Thunderstorms | 7 to 13 mph N | 70% |
| Tuesday | 73°F | Slight Chance Rain Showers then Mostly Cloudy | 13 mph N | 23% |
| Tuesday Night | 54°F | Mostly Cloudy | 5 to 13 mph N | 5% |
| Wednesday | 76°F | Mostly Sunny | 7 to 10 mph N | 2% |
| Wednesday Night | 56°F | Partly Cloudy | 2 to 9 mph N | 1% |
| Thursday | 77°F | Mostly Sunny | 3 to 8 mph N | 3% |
| Thursday Night | 58°F | Partly Cloudy | 3 to 7 mph NE | 3% |
Forecast source: National Weather Service (api.weather.gov) for West Alton (38.863, -90.204). Updated through the day.
Growing snapshot for West Alton
Last spring frost
Apr 4
First fall frost
Nov 5
Growing season
214 days
Hardiness zone
7a
More local growing data for West Alton: nearby ZIP 63386 weather · frost dates · planting calendar · Missouri frost dates
Nearby towns & communities
Augusta
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O'Fallon
St. Paul
St. Peters
Weldon Spring
Weldon Spring Heights
Wentzville
Climate data from the nearest NOAA station, Alton - Melvin Price L&D, Il (3.8 mi from West Alton). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.