Lake Forest Weather Forecast

    • 62
    • 81

    Chance Rain Showers

    • 56
    • 77

    Partly Sunny

    • 63
    • 78

    Rain Showers

    • 58
    • 76

    Chance Rain Showers

    • 59
    • 72

    Chance Rain Showers

    • 60
    • 76

    Chance Rain Showers

Today 17 Sep Summit

Mostly cloudy with a chance of Showers with a slight chance of Thunderstorms. Humid with Highs in the lower 80s. West Winds 5 to 10 Mph. Chance of rain 50 percent.

Tonight 17 Sep Summit

Mostly cloudy. A slight chance of Showers and Thunderstorms in the evening. Humid with Lows in the lower 60s. North Winds around 5 Mph. Chance of rain 20 percent.

Graph Plots Open in Graphs

  • Temperature Forecast NOAA

  • Temperature Real-Time

Lake Forest Temperature Statistics

September Temperature

Portage County Airport (11.2 miles)

  • Lowest 14 September, 2026

    50 °F

  • Average September

    69.5 °F

  • Highest 2 September, 2026

    91 °F

Climate (2021–2026)

Portage County Airport (11.2 miles)

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

  • Average Low 2021–2026

    40.5 °F

  • Average 2021–2026

    50 °F

  • Average High 2021–2026

    60 °F
Get WillyWeather+ to remove ads