Brentwood Weather Forecast

    • 74
    • 99

    Hot

    • 70
    • 99

    Hot

    • 67
    • 92

    Breezy

    • 68
    • 91

    Mostly Sunny

    • 69
    • 94

    Mostly Sunny

    • 68
    • 95

    Breezy

Today 19 Mar San Bernardino and Riverside County Valleys-The Inland Empire

Sunny, hot. Highs 97 to 103. Light Winds becoming west 10 Mph this afternoon.

Tonight 19 Mar San Bernardino and Riverside County Valleys-The Inland Empire

Clear. Lows 60 to 64 in wind Sheltered Areas to 64 to 73 in warmer Locations. Areas of Winds west to 10 Mph in the evening becoming light.

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  • Temperature Real-Time

Brentwood Temperature Statistics

March Temperature

Ontario International Airport (8.1 miles)

  • Lowest 6 March, 2026

    51.1 °F

  • Average March

    67.7 °F

  • Highest 16 March, 2026

    93.9 °F

Climate (2021–Present)

Ontario International Airport (8.1 miles)

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  • Average Low 2021–2026

    55.7 °F

  • Average 2021–2026

    66.9 °F

  • Average High 2021–2026

    79.2 °F
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