Williamsport Weather Forecast

    • 54
    • 69

    Rain Showers

    • 52
    • 69

    Rain Showers

    • 49
    • 62

    Rain Showers

    • 47
    • 64

    Mostly Cloudy

    • 47
    • 63

    Mostly Cloudy

    • 48
    • 66

    Partly Sunny

    • 49
    • 69

    Partly Sunny

Today 20 Sep Southern Lycoming

Mostly sunny. Highs in the lower 70s.

Tonight 20 Sep Southern Lycoming

Mostly cloudy. A slight chance of rain this evening. Patchy fog. Lows in the lower 50s. North Winds 5 to 10 Mph. Gusts up to 25 Mph after midnight. Chance of rain 20 percent.

Graph Plots Open in Graphs

  • Temperature Forecast NOAA

  • Temperature Real-Time

Williamsport Temperature Statistics

September Temperature

Williamsport - Lycoming County Airport (3.7 miles)

  • Lowest 15 September, 2026

    47.6 °F

  • Average September

    71.1 °F

  • Highest 1 September, 2026

    92.6 °F

Climate (2021–2026)

Williamsport - Lycoming County Airport (3.7 miles)

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

  • Average Low 2021–2026

    43.5 °F

  • Average 2021–2026

    53 °F

  • Average High 2021–2026

    63.3 °F
Get WillyWeather+ to remove ads