Lake St. Louis, MO Weather & Growing Conditions
Today
89°F
Sunny
Sunny, with a high near 89. South wind around 5 mph.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 89°F | Sunny | 5 mph S | 0% |
| Tonight | 69°F | Mostly Clear | 5 mph S | 0% |
| Wednesday | 91°F | Mostly Sunny then Isolated Showers And Thunderstorms | 5 mph S | 19% |
| Wednesday Night | 71°F | Chance Showers And Thunderstorms | 5 mph S | 71% |
| Thursday | 87°F | Showers And Thunderstorms Likely | 3 mph S | 71% |
| Thursday Night | 69°F | Partly Cloudy then Slight Chance Showers And Thunderstorms | 2 mph SE | 20% |
| Friday | 88°F | Slight Chance Showers And Thunderstorms then Partly Sunny | 2 mph SW | 20% |
| Friday Night | 70°F | Chance Showers And Thunderstorms | 2 mph S | 29% |
| Saturday | 90°F | Chance Showers And Thunderstorms then Mostly Sunny | 3 mph SW | 29% |
| Saturday Night | 72°F | Mostly Clear | 5 mph S | 5% |
| Sunday | 92°F | Sunny | 7 mph SW | 3% |
| Sunday Night | 74°F | Mostly Clear | 7 mph S | 4% |
| Monday | 94°F | Sunny | 7 mph SW | 4% |
| Monday Night | 75°F | Mostly Clear then Slight Chance Rain Showers | 3 to 7 mph SW | 15% |
Forecast source: National Weather Service (api.weather.gov). Updated through the day.
Growing snapshot for Lake St. Louis, MO
Last spring frost
Apr 10
First fall frost
Oct 26
Growing season
199 days
Hardiness zone
6b
Explore more for Lake St. Louis, MO: full frost dates · planting calendar · Missouri frost dates
Climate data from the nearest NOAA station, Weldon Spring Nws, Mo (8 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Aug 4, 2026.