O'Fallon Weather Forecast

    • 67
    • 78

    Rain Showers Likely

    • 72
    • 89

    Chance Thunderstorms

    • 76
    • 95

    Mostly Sunny

    • 77
    • 99

    Hot

    • 74
    • 95

    Partly Sunny

    • 72
    • 92

    Partly Sunny

Today 24 Jul St. Charles

Partly sunny this Morning, then mostly cloudy with a chance of Showers this afternoon. Highs in the upper 70s. Southeast Winds around 5 Mph. Chance of rain 50 percent.

Tonight 24 Jul St. Charles

Mostly cloudy with a chance of Showers with a slight chance of Thunderstorms. Lows in the upper 60s. Southeast Winds around 5 Mph. Chance of rain 50 percent.

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  • Temperature Real-Time

O'Fallon Temperature Statistics

July Temperature

St. Louis, Spirit Of St. Louis Airport (10.6 miles)

  • Lowest 13 July, 2026

    64.7 °F

  • Average July

    80.8 °F

  • Highest 2 July, 2026

    96.7 °F

Climate (2021–2026)

St. Louis, Spirit Of St. Louis Airport (10.6 miles)

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  • Average Low 2021–2026

    46.1 °F

  • Average 2021–2026

    57.5 °F

  • Average High 2021–2026

    68.9 °F
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