Joliet Weather Forecast

    • 69
    • 96

    Decreasing Clouds

    • 67
    • 96

    Mostly Sunny

    • 70
    • 96

    Mostly Sunny

    • 71
    • 96

    Slight Chance Thunderstorms

    • 71
    • 97

    Chance Rain Showers

    • 70
    • 96

    Chance Thunderstorms

    • 67
    • 93

    Chance Rain Showers

Today 18 Sep Caldwell

Mostly sunny this Morning, then partly cloudy with a slight chance of Showers and Thunderstorms this afternoon. Highs in the mid 90s. Southwest Winds around 5 Mph, becoming southeast around 5 Mph this afternoon.

Tonight 18 Sep Caldwell

Partly cloudy. Lows around 70. Southeast Winds 5 to 10 Mph, becoming southwest after midnight.

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Joliet Temperature Statistics

September Temperature

San Marcos, San Marcos Municipal Airport (13.7 miles)

  • Lowest 9 September, 2025

    61 °F

  • Average September

    81.1 °F

  • Highest 4 September, 2025

    102 °F

Climate (2020–Present)

San Marcos, San Marcos Municipal Airport (13.7 miles)

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  • Average Low 2020–2025

    59.2 °F

  • Average 2020–2025

    69.9 °F

  • Average High 2020–2025

    81.6 °F
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