Fontana Weather Forecast

    • 55
    • 65

    Rain Showers

    • 55
    • 68

    Decreasing Clouds

    • 57
    • 75

    Sunny

    • 58
    • 78

    Mostly Sunny

    • 58
    • 79

    Mostly Sunny

    • 57
    • 77

    Partly Sunny

    • 57
    • 75

    Partly Sunny

Today 22 Oct San Bernardino and Riverside County Valleys-The Inland Empire

Partly cloudy. Highs 70 to 75.

Tonight 22 Oct San Bernardino and Riverside County Valleys-The Inland Empire

Partly cloudy this evening. Becoming mostly cloudy. A slight chance of Showers. Cooler. Lows 48 to 54. Areas of Winds southwest to 10 Mph this evening becoming light. Chance of measurable precipitation 20 percent.

Graph Plots Open in Graphs

  • Temperature Forecast NOAA

  • Temperature Real-Time

Fontana Temperature Statistics

October Temperature

Ontario International Airport (8.1 miles)

  • Lowest 14 October, 2026

    52.6 °F

  • Average October

    78.5 °F

  • Highest 5 October, 2026

    104.6 °F

Climate (2021–2026)

Ontario International Airport (8.1 miles)

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

  • Average Low 2021–2026

    55.9 °F

  • Average 2021–2026

    67.3 °F

  • Average High 2021–2026

    79.4 °F
Get WillyWeather+ to remove ads