Fontana Weather Forecast

    • 70
    • 97

    Hot

    • 72
    • 99

    Hot

    • 70
    • 100

    Hot

    • 68
    • 96

    Mostly Sunny

    • 68
    • 94

    Mostly Sunny

    • 66
    • 92

    Mostly Sunny

Today 7 Aug San Bernardino and Riverside County Valleys-The Inland Empire

Mostly sunny. Highs 93 to 100. Areas of Winds southwest to 10 Mph becoming west with Gusts to 25 Mph this afternoon.

Tonight 7 Aug San Bernardino and Riverside County Valleys-The Inland Empire

Mostly clear. Lows 65 to 70. Areas of Winds west 10 to 15 Mph with Gusts to 25 Mph in the evening becoming light.

Graph Plots Open in Graphs

  • Temperature Forecast NOAA

  • Temperature Real-Time

Fontana Temperature Statistics

August Temperature

Ontario International Airport (8.1 miles)

  • Lowest 5 August, 2026

    66.9 °F

  • Average August

    83.1 °F

  • Highest 1 August, 2026

    102.7 °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

    55.8 °F

  • Average 2021–2026

    67.1 °F

  • Average High 2021–2026

    79.3 °F
Get WillyWeather+ to remove ads