Lake St. Louis, MO Weather & Growing Conditions
Overnight
74°F
Mostly Clear
Mostly clear, with a low around 74. South wind around 5 mph.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Overnight | 74°F | Mostly Clear | 5 mph S | 4% |
| Saturday | 97°F | Partly Sunny | 3 to 8 mph SW | 4% |
| Saturday Night | 73°F | Partly Cloudy | 1 to 5 mph SW | 4% |
| Sunday | 90°F | Slight Chance Rain Showers then Slight Chance Showers And Thunderstorms | 2 to 6 mph W | 43% |
| Sunday Night | 66°F | Showers And Thunderstorms Likely | 7 mph N | 72% |
| Monday | 76°F | Showers And Thunderstorms Likely | 6 to 10 mph NE | 72% |
| Monday Night | 58°F | Chance Showers And Thunderstorms | 6 to 10 mph NE | 30% |
| Tuesday | 69°F | Slight Chance Rain Showers then Mostly Cloudy | 8 to 12 mph N | 19% |
| Tuesday Night | 53°F | Mostly Cloudy | 3 to 9 mph N | 2% |
| Wednesday | 73°F | Mostly Sunny | 5 to 8 mph N | 1% |
| Wednesday Night | 54°F | Partly Cloudy | 1 to 6 mph N | 0% |
| Thursday | 75°F | Mostly Sunny | 2 to 6 mph NE | 3% |
| Thursday Night | 57°F | Mostly Cloudy | 1 to 6 mph NE | 4% |
| Friday | 76°F | Partly Sunny | 2 to 6 mph NE | 8% |
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 Sep 19, 2026.