Diamond Bar Weather Forecast

    • 66
    • 90

    Mostly Cloudy

    • 68
    • 96

    Mostly Sunny

    • 71
    • 101

    Hot

    • 66
    • 97

    Mostly Sunny

    • 64
    • 88

    Partly Sunny

    • 65
    • 89

    Partly Sunny

    • 65
    • 90

    Mostly Sunny

Today 13 Jul Los Angeles County San Gabriel Valley

Partly cloudy in the morning then mostly cloudy. Highs around 90.

Tonight 13 Jul Los Angeles County San Gabriel Valley

Mostly cloudy in the evening then partly cloudy. Lows in the mid to upper 60s.

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Diamond Bar Temperature Statistics

July Temperature

Brackett Field Airport (4.3 miles)

  • Lowest 3 July, 2026

    59 °F

  • Average July

    77.3 °F

  • Highest 7 July, 2026

    91.4 °F

Climate (2021–2026)

Brackett Field Airport (4.3 miles)

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  • Average Low 2021–2026

    55.9 °F

  • Average 2021–2026

    67.9 °F

  • Average High 2021–2026

    75.9 °F
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