La Mesa Weather Forecast

    • 69
    • 84

    Chance Thunderstorms

    • 66
    • 82

    Partly Sunny

    • 66
    • 82

    Partly Sunny

    • 66
    • 82

    Partly Sunny

    • 66
    • 85

    Partly Sunny

    • 66
    • 83

    Mostly Sunny

Today 18 Sep San Diego County Inland Valleys

Partly cloudy with a chance of Showers. A slight chance of Thunderstorms this Morning, then a chance of Thunderstorms this afternoon. Highs 83 to 88. Areas of Winds southwest to 10 Mph becoming west this afternoon. Chance of measurable precipitation 50 percent.

Tonight 18 Sep San Diego County Inland Valleys

Partly cloudy. A slight chance of Showers and Thunderstorms in the evening. Lows 63 to 67. Areas of Winds west to 10 Mph in the evening becoming light. Chance of measurable precipitation 20 percent.

Graph Plots Open in Graphs

  • Temperature Forecast NOAA

  • Temperature Real-Time

La Mesa Temperature Statistics

September Temperature

Gillespie Field Airport (5 miles)

  • Lowest 6 September, 2025

    62.6 °F

  • Average September

    72 °F

  • Highest 16 September, 2025

    96.8 °F

Climate (2020–Present)

Gillespie Field Airport (5 miles)

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

  • Average Low 2020–2025

    52.9 °F

  • Average 2020–2025

    60.2 °F

  • Average High 2020–2025

    75.9 °F
Get WillyWeather+ to remove ads