Fountain Valley Weather Forecast

    • 65
    • 81

    Mostly Sunny

    • 67
    • 86

    Mostly Sunny

    • 68
    • 82

    Chance Thunderstorms

    • 68
    • 83

    Chance Rain Showers

    • 68
    • 82

    Slight Chance Thunderstorms

    • 68
    • 81

    Partly Sunny

Today 15 Sep Orange County Inland

Partly cloudy with patchy fog this morning. Becoming sunny. Highs 80 to 84 towards the coast to 90 farther inland. Light Winds becoming southwest 10 Mph this afternoon.

Tonight 15 Sep Orange County Inland

Clear in the evening. Becoming partly cloudy overnight with patchy fog. Lows 63 to 67. Light Winds.

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Fountain Valley Temperature Statistics

September Temperature

John Wayne-Orange County Airport (5 miles)

  • Lowest 12 September, 2025

    64.9 °F

  • Average September

    72.8 °F

  • Highest 3 September, 2025

    86 °F

Climate (2020–Present)

John Wayne-Orange County Airport (5 miles)

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  • Average Low 2020–2025

    58.7 °F

  • Average 2020–2025

    65.7 °F

  • Average High 2020–2025

    73.6 °F
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