Costa Mesa Weather Forecast

    • 73
    • 95

    Mostly Sunny

    • 70
    • 85

    Mostly Sunny

    • 67
    • 81

    Partly Sunny

    • 65
    • 78

    Partly Sunny

    • 64
    • 78

    Mostly Sunny

    • 63
    • 77

    Mostly Sunny

    • 62
    • 76

    Mostly Sunny

Today 9 Sep Orange County Coastal

Mostly sunny. Highs 89 to 94 at the Beaches to 99 to 104 farther inland and near higher coastal Terrain. Light Winds becoming south 10 Mph this afternoon.

Tonight 9 Sep Orange County Coastal

Mostly clear this evening. Becoming partly cloudy. Lows 71 to 74. Areas of Winds south to 10 Mph.

Graph Plots Open in Graphs

  • Temperature Forecast NOAA

  • Temperature Real-Time

Costa Mesa Temperature Statistics

September Temperature

John Wayne-Orange County Airport (3.7 miles)

  • Lowest 2 September, 2026

    65.6 °F

  • Average September

    74.6 °F

  • Highest 7 September, 2026

    91.9 °F

Climate (2021–2026)

John Wayne-Orange County Airport (3.7 miles)

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

  • Average Low 2021–2026

    59 °F

  • Average 2021–2026

    66.1 °F

  • Average High 2021–2026

    73.8 °F
Get WillyWeather+ to remove ads