Summerville Weather Forecast

    • 74
    • 95

    Slight Chance Thunderstorms

    • 73
    • 94

    Slight Chance Thunderstorms

    • 71
    • 91

    Chance Thunderstorms

    • 65
    • 82

    Partly Sunny

    • 64
    • 82

    Mostly Sunny

    • 65
    • 84

    Mostly Sunny

Today 17 Aug Macoupin

Mostly sunny. A slight chance of Showers and Thunderstorms in the afternoon. Hot with Highs in the mid 90s. South Winds around 5 Mph. Chance of rain 20 percent. Heat index Values up to 106.

Tonight 17 Aug Macoupin

Mostly clear. Near steady temperature in the mid 70s. South Winds around 5 Mph.

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  • Temperature Real-Time

Summerville Temperature Statistics

August Temperature

St. Louis Regional Airport (21.1 miles)

  • Lowest 3 August, 2025

    56.7 °F

  • Average August

    73.4 °F

  • Highest 8 August, 2025

    91.4 °F

Climate (2020–Present)

St. Louis Regional Airport (21.1 miles)

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  • Average Low 2020–2025

    46.1 °F

  • Average 2020–2025

    53.9 °F

  • Average High 2020–2025

    66 °F
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