Saint Charles Weather Forecast

    • 71
    • 97

    Slight Chance Thunderstorms

    • 71
    • 98

    Slight Chance Thunderstorms

    • 71
    • 95

    Slight Chance Thunderstorms

    • 69
    • 95

    Slight Chance Thunderstorms

    • 69
    • 94

    Partly Sunny

    • 65
    • 88

    Chance Rain Showers

Today 13 Sep St. Charles

Mostly sunny. Hot with Highs in the mid 90s. Southwest Winds around 5 Mph.

Tonight 13 Sep St. Charles

Partly cloudy. Lows around 70. South Winds around 5 Mph.

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Saint Charles Temperature Statistics

September Temperature

St. Louis Lambert International Airport (6.2 miles)

  • Lowest 7 September, 2025

    52 °F

  • Average September

    69.4 °F

  • Highest 11 September, 2025

    89.1 °F

Climate (2020–Present)

St. Louis Lambert International Airport (6.2 miles)

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  • Average Low 2020–2025

    50.3 °F

  • Average 2020–2025

    59.7 °F

  • Average High 2020–2025

    69.1 °F
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