Downtown Fontana Weather Forecast

    • 58
    • 81

    Increasing Clouds

    • 63
    • 87

    Mostly Sunny

    • 66
    • 96

    Mostly Sunny

    • 65
    • 90

    Mostly Cloudy

    • 60
    • 82

    Slight Chance Rain Showers

    • 55
    • 76

    Partly Sunny

Today 28 May San Bernardino and Riverside County Valleys-The Inland Empire

Patchy fog this morning. Partly cloudy. Highs 80 to 86. Light Winds becoming west 10 to 15 Mph with Gusts to 25 Mph this afternoon.

Tonight 28 May San Bernardino and Riverside County Valleys-The Inland Empire

Partly cloudy. Patchy fog overnight. Lows 51 to 57. Areas of Winds southwest 10 to 15 Mph in the evening becoming light.

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  • Temperature Forecast NOAA

  • Temperature Real-Time

Downtown Fontana Temperature Statistics

May Temperature

Ontario International Airport (8.7 miles)

  • Lowest 4 May, 2025

    53.7 °F

  • Average May

    68.6 °F

  • Highest 10 May, 2025

    103.6 °F

Climate (2020–Present)

Ontario International Airport (8.7 miles)

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  • Average Low 2020–2025

    55.6 °F

  • Average 2020–2025

    66.6 °F

  • Average High 2020–2025

    79.1 °F
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