Summit Weather Forecast

    • 66
    • 80

    Thunderstorms Likely

    • 62
    • 80

    Slight Chance Thunderstorms

    • 60
    • 76

    Partly Sunny

    • 62
    • 77

    Partly Sunny

    • 66
    • 79

    Mostly Cloudy

    • 66
    • 81

    Slight Chance Thunderstorms

Today 21 Aug Central Cook

Mostly cloudy. A slight chance of Showers and Thunderstorms early in the afternoon. A chance of Showers and Thunderstorms late. Highs in the upper 70s. Southwest Winds around 5 Mph, increasing to south in the afternoon. Chance of precipitation 50 percent.

Tonight 21 Aug Central Cook

Mostly cloudy. Showers and Thunderstorms likely early in the Evening, then a chance of Showers and Thunderstorms late in the evening. A slight chance of Showers and Thunderstorms after midnight. Lows in the mid 60s. Southwest Winds 5 to 10 Mph. Chance of precipitation 60 percent.

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Summit Temperature Statistics

August Temperature

Chicago, Chicago Midway Airport (2.5 miles)

  • Lowest 3 August, 2026

    63 °F

  • Average August

    75.1 °F

  • Highest 10 August, 2026

    87.1 °F

Climate (2021–2026)

Chicago, Chicago Midway Airport (2.5 miles)

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  • Average Low 2021–2026

    46.7 °F

  • Average 2021–2026

    54.3 °F

  • Average High 2021–2026

    61.9 °F
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