Etiwanda Weather Forecast

    • 61
    • 82

    Becoming Sunny

    • 64
    • 87

    Mostly Sunny

    • 63
    • 85

    Partly Sunny

    • 61
    • 81

    Mostly Sunny

    • 64
    • 86

    Mostly Sunny

    • 66
    • 91

    Mostly Sunny

Today 18 Sep San Bernardino and Riverside County Valleys-The Inland Empire

Mostly sunny. Highs 81 to 86. Light Winds becoming west 10 to 15 Mph with Gusts to 25 Mph this afternoon.

Tonight 18 Sep San Bernardino and Riverside County Valleys-The Inland Empire

Mostly clear. Lows 52 to 60. Areas of Winds west 10 to 15 Mph in the evening becoming light.

Graph Plots Open in Graphs

  • Temperature Forecast NOAA

  • Temperature Real-Time

Etiwanda Temperature Statistics

September Temperature

Ontario International Airport (5.6 miles)

  • Lowest 2 September, 2026

    63.6 °F

  • Average September

    80.2 °F

  • Highest 9 September, 2026

    109.7 °F

Climate (2021–2026)

Ontario International Airport (5.6 miles)

Take a look at our website widgetsAvailable free! Find Out More

  • Average Low 2021–2026

    55.8 °F

  • Average 2021–2026

    67.2 °F

  • Average High 2021–2026

    79.3 °F
Get WillyWeather+ to remove ads