Mount Pleasant Weather Forecast

    • 74
    • 99

    Slight Chance Thunderstorms

    • 75
    • 98

    Hot

    • 68
    • 94

    Rain Showers Likely

    • 62
    • 81

    Rain Showers Likely

    • 56
    • 72

    Mostly Cloudy

    • 56
    • 74

    Partly Sunny

    • 59
    • 75

    Partly Sunny

Today 18 Sep St. Louis City

Sunny with a chance of Showers and Thunderstorms. Hot. Near steady temperature in the mid 90s. Southeast Winds around 5 Mph. Chance of rain 30 percent. Heat index Values up to 107.

Tonight 18 Sep St. Louis City

Mostly clear. A slight chance of Showers and Thunderstorms this evening. Lows in the lower 70s. Southeast Winds around 5 Mph. Chance of rain 20 percent. Heat index Values up to 102 early this evening.

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Mount Pleasant Temperature Statistics

September Temperature

St. Louis Downtown Airport (4.3 miles)

  • Lowest 8 September, 2026

    59.6 °F

  • Average September

    81.4 °F

  • Highest 5 September, 2026

    102.7 °F

Climate (2021–2026)

St. Louis Downtown Airport (4.3 miles)

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  • Average Low 2021–2026

    47.8 °F

  • Average 2021–2026

    58.6 °F

  • Average High 2021–2026

    69.5 °F
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