Saint Charles Weather Forecast

    • 77
    • 94

    Chance Thunderstorms

    • 77
    • 96

    Chance Thunderstorms

    • 78
    • 96

    Slight Chance Thunderstorms

    • 79
    • 98

    Hot

    • 79
    • 100

    Hot

    • 77
    • 99

    Hot

Today 19 Jul St. Charles

Partly sunny with a chance of Showers and Thunderstorms. Humid with Highs in the lower 90s. Southwest Winds 5 to 10 Mph. Chance of rain 50 percent. Heat index Values up to 106.

Tonight 19 Jul St. Charles

A slight chance of Thunderstorms in the evening. Mostly clear with a slight chance of Showers. Humid with Lows in the mid 70s. Southwest Winds around 5 Mph. Chance of rain 20 percent. Heat index Values up to 104 early in the evening.

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Saint Charles Temperature Statistics

July Temperature

St. Louis Lambert International Airport (6.2 miles)

  • Lowest 2 July, 2025

    68 °F

  • Average July

    81.3 °F

  • Highest 11 July, 2025

    94.6 °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

    59.6 °F

  • Average High 2020–2025

    69 °F
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