Lake Saint Louis Weather Forecast

    • 71
    • 94

    Rain Showers

    • 63
    • 78

    Thunderstorms Likely

    • 66
    • 85

    Partly Sunny

    • 67
    • 90

    Chance Thunderstorms

    • 67
    • 87

    Chance Thunderstorms

    • 67
    • 90

    Chance Thunderstorms

Today 9 Sep St. Charles

Mostly sunny. A slight chance of Showers this Morning, then a chance of Showers and Thunderstorms this afternoon. Highs in the mid 90s. Southwest Winds 5 to 10 Mph, becoming west this afternoon. Chance of rain 50 percent. Heat index Values up to 103.

Tonight 9 Sep St. Charles

Thunderstorms likely. Showers with Lows in the lower 70s. Northwest Winds around 5 Mph. Chance of rain near 100 percent.

Graph Plots Open in Graphs

  • Temperature Forecast NOAA

  • Temperature Real-Time

Lake Saint Louis Temperature Statistics

September Temperature

St. Louis, Spirit Of St. Louis Airport (11.2 miles)

  • Lowest 1 September, 2026

    71.7 °F

  • Average September

    85.8 °F

  • Highest 5 September, 2026

    102.7 °F

Climate (2021–2026)

St. Louis, Spirit Of St. Louis Airport (11.2 miles)

Take a look at our website widgetsAvailable free! Find Out More

  • Average Low 2021–2026

    46.1 °F

  • Average 2021–2026

    57.5 °F

  • Average High 2021–2026

    69 °F
Get WillyWeather+ to remove ads