Lake Riverside Weather Forecast

    • 67
    • 91

    Slight Chance Thunderstorms

    • 68
    • 95

    Partly Sunny

    • 65
    • 92

    Slight Chance Thunderstorms

    • 57
    • 89

    Sunny

    • 51
    • 84

    Mostly Sunny

    • 52
    • 83

    Sunny

Today 8 Sep Riverside County Mountains

Partly cloudy. A slight chance of Showers and Thunderstorms this afternoon. Warmer. Highs 82 to 92. Light Winds becoming west 10 Mph this afternoon. Chance of measurable precipitation 20 percent.

Tonight 8 Sep Riverside County Mountains

Partly cloudy in the evening. Becoming mostly clear. Lows 60 to 70. Areas of Winds west 10 Mph in the evening becoming light.

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  • 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

    59.4 °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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