Diamond Bar Weather Forecast

    • 58
    • 82

    Mostly Sunny

    • 55
    • 74

    Rain Showers

    • 53
    • 67

    Chance Rain Showers

    • 54
    • 71

    Mostly Sunny

    • 56
    • 77

    Mostly Sunny

    • 57
    • 79

    Mostly Sunny

Today 20 Oct Los Angeles County San Gabriel Valley

Partly cloudy in the morning then sunny. Highs around 80.

Tonight 20 Oct Los Angeles County San Gabriel Valley

Mostly clear in the evening then mostly cloudy. Lows in the mid 50s to around 60.

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  • Temperature Forecast NOAA

  • Temperature Real-Time

Diamond Bar Temperature Statistics

October Temperature

Brackett Field Airport (4.3 miles)

  • Lowest 13 October, 2026

    51.8 °F

  • Average October

    81 °F

  • Highest 2 October, 2026

    102.2 °F

Climate (2021–2026)

Brackett Field Airport (4.3 miles)

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  • Average Low 2021–2026

    56.2 °F

  • Average 2021–2026

    68.2 °F

  • Average High 2021–2026

    76.1 °F
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