Grand Terrace Weather Forecast

    • 64
    • 91

    Becoming Sunny

    • 67
    • 94

    Sunny

    • 68
    • 96

    Hot

    • 69
    • 95

    Mostly Sunny

    • 68
    • 93

    Slight Chance Thunderstorms

    • 66
    • 91

    Slight Chance Thunderstorms

Today 14 Sep San Bernardino and Riverside County Valleys-The Inland Empire

Partly cloudy with patchy fog this morning. Becoming sunny. Warmer. Highs 88 to 93. Light Winds becoming west 10 to 15 Mph this afternoon.

Tonight 14 Sep San Bernardino and Riverside County Valleys-The Inland Empire

Clear. Lows 60 to 65. Areas of Winds west to 10 Mph in the evening becoming light.

Graph Plots Open in Graphs

  • Temperature Forecast NOAA

  • Temperature Real-Time

Grand Terrace Temperature Statistics

September Temperature

San Bernardino Intl. Airport (5 miles)

  • Lowest 9 September, 2025

    60.8 °F

  • Average September

    77.1 °F

  • Highest 1 September, 2025

    100.4 °F

Climate (2020–Present)

San Bernardino Intl. Airport (5 miles)

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

  • Average Low 2020–2025

    54.1 °F

  • Average 2020–2025

    63.2 °F

  • Average High 2020–2025

    80.5 °F
Get WillyWeather+ to remove ads