Lake St. Louis, MO Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Lake St. Louis, a city in St. Charles County, Missouri.
Today
58°F
Patchy Drizzle then Mostly Cloudy
Patchy drizzle before noon. Mostly cloudy, with a high near 58. West wind 8 to 13 mph, with gusts as high as 21 mph.
7-day forecast for Lake St. Louis
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 58°F | Patchy Drizzle then Mostly Cloudy | 8 to 13 mph W | 12% |
| Tonight | 42°F | Partly Cloudy | 6 mph W | 0% |
| Thursday | 64°F | Sunny | 6 to 10 mph W | 0% |
| Thursday Night | 43°F | Mostly Cloudy | 6 mph NW | 3% |
| Friday | 56°F | Partly Sunny | 6 to 10 mph N | 5% |
| Friday Night | 33°F | Partly Cloudy | 1 to 5 mph N | 0% |
| Saturday | 55°F | Mostly Sunny | 3 mph N | 0% |
| Saturday Night | 33°F | Partly Cloudy | 2 mph NW | 0% |
| Sunday | 61°F | Sunny | 2 to 6 mph NW | 1% |
| Sunday Night | 34°F | Clear | 1 mph W | 0% |
| Monday | 66°F | Sunny | 1 to 5 mph SW | 0% |
| Monday Night | 40°F | Clear | 3 mph SW | 0% |
| Tuesday | 69°F | Sunny | 3 mph W | 1% |
| Tuesday Night | 41°F | Mostly Clear | 1 mph N | 2% |
Forecast source: National Weather Service (api.weather.gov) for Lake St. Louis (38.780, -90.786). Updated through the day.
Growing snapshot for Lake St. Louis
Last spring frost
Apr 10
First fall frost
Oct 26
Growing season
199 days
Hardiness zone
6b
More local growing data for Lake St. Louis: nearby ZIP 63367 weather · frost dates · planting calendar · Missouri frost dates
Nearby towns & communities
Augusta
Cottleville
Dardenne Prairie
Defiance
Flint Hill
Foristell
Josephville
New Melle
O'Fallon
St. Paul
St. Peters
Weldon Spring
Weldon Spring Heights
Wentzville
West Alton
Climate data from the nearest NOAA station, Weldon Spring Nws, Mo (8 mi from Lake St. Louis). Frost dates are 1991–2020 averages, not a forecast. Page updated Nov 4, 2026.