Lake Riverside Weather Forecast

    • 59
    • 83

    Chance Rain Showers

    • 60
    • 79

    Chance Rain Showers

    • 60
    • 84

    Mostly Sunny

    • 62
    • 88

    Mostly Sunny

    • 63
    • 89

    Partly Sunny

    • 60
    • 89

    Slight Chance Thunderstorms

Today 5 Sep Riverside County Mountains

Mostly sunny this Morning, then partly cloudy with a slight chance of Showers this afternoon. Highs 76 to 86. Areas of Winds southwest 10 to 15 Mph. Gusts to 30 Mph. Becoming 25 Mph this afternoon. Chance of measurable precipitation less than 20 percent.

Tonight 5 Sep Riverside County Mountains

Partly cloudy with a slight chance of Showers in the Evening, then cloudy with a chance of Showers overnight. Lows 53 to 63. Areas of Winds west 10 to 15 Mph with Gusts to 25 Mph. Chance of measurable precipitation 30 percent.

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  • Temperature Forecast NOAA

  • Temperature Real-Time

Lake Riverside Temperature Statistics

September Temperature

Big Bear City Airport (51.6 miles)

  • Lowest 1 September, 2026

    41.2 °F

  • Average September

    59.8 °F

  • Highest 3 September, 2026

    72.1 °F

Climate (2021–2026)

Big Bear City Airport (51.6 miles)

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  • Average Low 2021–2026

    33.8 °F

  • Average 2021–2026

    48.9 °F

  • Average High 2021–2026

    60.4 °F
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