Lake Riverside Weather Forecast

    • 56
    • 79

    Rain Showers

    • 53
    • 79

    Mostly Sunny

    • 54
    • 82

    Mostly Sunny

    • 56
    • 80

    Slight Chance Rain Showers

    • 59
    • 83

    Slight Chance Rain Showers

    • 58
    • 83

    Slight Chance Thunderstorms

    • 55
    • 83

    Mostly Sunny

Today 18 Sep Riverside County Mountains

Showers likely and a slight chance of Thunderstorms this Morning, then Showers and a chance of Thunderstorms this afternoon. Highs 69 to 79. Areas of Winds south 10 Mph becoming west this afternoon.

Tonight 18 Sep Riverside County Mountains

Partly cloudy with a chance of Showers and a slight chance of Thunderstorms this Evening, then mostly clear overnight. Cooler. Lows 49 to 59. Areas of Winds west to 10 Mph. Chance of measurable precipitation 40 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 12 September, 2025

    32 °F

  • Average September

    57.7 °F

  • Highest 1 September, 2025

    78.8 °F

Climate (2020–Present)

Big Bear City Airport (51.6 miles)

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  • Average Low 2020–2025

    34.1 °F

  • Average 2020–2025

    49.3 °F

  • Average High 2020–2025

    60.1 °F
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