Fullerton Weather Forecast

    • 59
    • 81

    Sunny

    • 62
    • 85

    Sunny

    • 59
    • 86

    Mostly Sunny

    • 56
    • 77

    Partly Sunny

    • 54
    • 72

    Mostly Sunny

    • 55
    • 80

    Sunny

    • 57
    • 85

    Sunny

Today 29 Jan Los Angeles County San Gabriel Valley

Sunny. Highs around 80.

Tonight 29 Jan Los Angeles County San Gabriel Valley

Clear. Lows in the upper 40s and 50s.

Graph Plots Open in Graphs

  • Temperature Forecast NOAA

  • Temperature Real-Time

Fullerton Temperature Statistics

January Temperature

Fullerton, Fullerton Municipal Airport (6.2 miles)

  • Lowest 10 January, 2026

    39.7 °F

  • Average January

    60.9 °F

  • Highest 14 January, 2026

    85.6 °F

Climate (2021–Present)

Fullerton, Fullerton Municipal Airport (6.2 miles)

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

  • Average Low 2021–2026

    56.9 °F

  • Average 2021–2026

    66.1 °F

  • Average High 2021–2026

    76.5 °F
Get WillyWeather+ to remove ads