Mount Vernon Weather Forecast

    • 65
    • 92

    Sunny

    • 69
    • 97

    Hot

    • 73
    • 102

    Hot

    • 73
    • 102

    Hot

    • 73
    • 99

    Hot

    • 72
    • 98

    Hot

    • 71
    • 98

    Hot

Today 30 Sep San Bernardino and Riverside County Valleys-The Inland Empire

Sunny, hot. Highs 96 to 102.

Tonight 30 Sep San Bernardino and Riverside County Valleys-The Inland Empire

Mostly clear. Lows 60 to 65. Areas of Winds west to 10 Mph this evening becoming light.

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Mount Vernon Temperature Statistics

September Temperature

San Bernardino Intl. Airport (4.3 miles)

  • Lowest 19 September, 2026

    57.2 °F

  • Average September

    74.2 °F

  • Highest 9 September, 2026

    105.8 °F

Climate (2021–2026)

San Bernardino Intl. Airport (4.3 miles)

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  • Average Low 2021–2026

    54.2 °F

  • Average 2021–2026

    63.2 °F

  • Average High 2021–2026

    80.3 °F
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