Collinsville Weather Forecast

    • 77
    • 92

    Chance Thunderstorms

    • 78
    • 96

    Slight Chance Thunderstorms

    • 78
    • 98

    Hot

    • 78
    • 100

    Hot

    • 75
    • 98

    Chance Rain Showers

    • 70
    • 89

    Slight Chance Rain Showers

Today 12 Aug Madison

Partly sunny. Isolated Showers and Thunderstorms. Near steady temperature in the lower 90s. Southwest Winds 5 to 10 Mph. Chance of rain 20 percent. Heat index Values up to 104.

Tonight 12 Aug Madison

Mostly cloudy with isolated Showers and Thunderstorms in the Evening, then partly cloudy with scattered Showers and Thunderstorms after midnight. Humid with Lows in the upper 70s. South Winds around 5 Mph. Chance of rain 30 percent. Heat index Values up to 104 early in the evening.

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Collinsville Temperature Statistics

August Temperature

Belleville, Scott AFB/MidAmerica Airport (10.6 miles)

  • Lowest 3 August, 2026

    64.8 °F

  • Average August

    77.7 °F

  • Highest 9 August, 2026

    92.1 °F

Climate (2021–2026)

Belleville, Scott AFB/MidAmerica Airport (10.6 miles)

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  • Average Low 2021–2026

    47.9 °F

  • Average 2021–2026

    57.9 °F

  • Average High 2021–2026

    68.1 °F
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