Cucamonga-Guasti Regional Park Weather Forecast

    • 59
    • 88

    Mostly Sunny

    • 61
    • 87

    Sunny

    • 63
    • 91

    Sunny

    • 63
    • 95

    Sunny

    • 59
    • 85

    Mostly Sunny

    • 58
    • 83

    Mostly Sunny

Today 8 May San Bernardino and Riverside County Valleys-The Inland Empire

Partly cloudy with patchy fog in the morning. Becoming sunny. Highs 82 to 88. Areas of Winds southwest to 10 Mph becoming west with Gusts to 25 Mph in the afternoon.

Tonight 8 May San Bernardino and Riverside County Valleys-The Inland Empire

Mostly clear. Lows 51 to 54 in wind Sheltered Areas to 53 to 61 in warmer Locations. Areas of Winds west to 10 Mph this evening becoming light.

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  • Temperature Real-Time

Cucamonga-Guasti Regional Park Temperature Statistics

May Temperature

Ontario International Airport (1.2 miles)

  • Lowest 6 May, 2026

    51.1 °F

  • Average May

    64.8 °F

  • Highest 2 May, 2026

    82.7 °F

Climate (2021–Present)

Ontario International Airport (1.2 miles)

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  • Average Low 2021–2026

    55.8 °F

  • Average 2021–2026

    67 °F

  • Average High 2021–2026

    79.3 °F
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