Mount Vernon Weather Forecast

    • 79
    • 106

    Hot

    • 75
    • 103

    Hot

    • 69
    • 97

    Hot

    • 63
    • 91

    Sunny

    • 62
    • 89

    Sunny

    • 61
    • 90

    Sunny

Today 9 Sep San Bernardino and Riverside County Valleys-The Inland Empire

Mostly sunny this Morning, then partly cloudy with a slight chance of Showers this afternoon. Hot. Highs 102 to 108. Areas of Winds north to 10 Mph becoming west this afternoon. Chance of measurable precipitation 20 percent.

Tonight 9 Sep San Bernardino and Riverside County Valleys-The Inland Empire

Mostly clear in the evening. Becoming partly cloudy. Lows 73 to 78. Areas of Winds north to 10 Mph in the evening becoming light.

Graph Plots Open in Graphs

  • Temperature Forecast NOAA

  • Temperature Real-Time

Mount Vernon Temperature Statistics

September Temperature

San Bernardino Intl. Airport (4.3 miles)

  • Lowest 2 September, 2026

    59 °F

  • Average September

    72.3 °F

  • Highest 5 September, 2026

    95 °F

Climate (2021–2026)

San Bernardino Intl. Airport (4.3 miles)

Take a look at our website widgetsAvailable free! Find Out More

  • Average Low 2021–2026

    54.2 °F

  • Average 2021–2026

    63.2 °F

  • Average High 2021–2026

    80.3 °F
Get WillyWeather+ to remove ads