Sierra Lakes Weather Forecast

    • 66
    • 92

    Increasing Clouds

    • 66
    • 85

    Slight Chance Rain Showers

    • 67
    • 91

    Mostly Sunny

    • 69
    • 94

    Sunny

    • 69
    • 96

    Mostly Sunny

    • 68
    • 96

    Sunny

    • 67
    • 94

    Sunny

Today 27 Aug San Bernardino and Riverside County Valleys-The Inland Empire

Mostly sunny. Highs 90 to 96. Areas of Winds west to 10 Mph. Becoming 10 to 15 Mph with Gusts to 25 Mph this afternoon.

Tonight 27 Aug San Bernardino and Riverside County Valleys-The Inland Empire

Partly cloudy this evening. Becoming mostly cloudy. Lows 63 to 68. Areas of Winds southwest 10 to 15 Mph this evening becoming light.

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Sierra Lakes Temperature Statistics

August Temperature

Ontario International Airport (9.3 miles)

  • Lowest 1 August, 2025

    61.6 °F

  • Average August

    81 °F

  • Highest 7 August, 2025

    103.6 °F

Climate (2020–Present)

Ontario International Airport (9.3 miles)

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  • Average Low 2020–2025

    55.5 °F

  • Average 2020–2025

    66.7 °F

  • Average High 2020–2025

    79.1 °F
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