Delaware River - Fort Delaware State Park Weather Forecast

    • 60
    • 66

    Rain Showers

    • 58
    • 66

    Mostly Cloudy

    • 57
    • 65

    Slight Chance Rain Showers

    • 60
    • 69

    Slight Chance Rain Showers

    • 61
    • 68

    Chance Rain Showers

    • 62
    • 69

    Partly Sunny

    • 62
    • 71

    Mostly Sunny

Today 22 Sep New Castle

Mostly sunny. Highs in the mid 70s.

Tonight 22 Sep New Castle

Cloudy. A chance of Showers, mainly this evening. Lows in the mid 50s. Northeast Winds 10 to 15 Mph with Gusts up to 25 Mph. Chance of rain 50 percent.

Graph Plots Open in Graphs

  • Temperature Forecast NOAA

  • Temperature Real-Time

Delaware River - Fort Delaware State Park Temperature Statistics

September Temperature

Wilmington, New Castle County Airport (5.6 miles)

  • Lowest 15 September, 2026

    52.6 °F

  • Average September

    74.8 °F

  • Highest 1 September, 2026

    93.7 °F

Climate (2021–2026)

Wilmington, New Castle County Airport (5.6 miles)

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

  • Average Low 2021–2026

    47.9 °F

  • Average 2021–2026

    57.4 °F

  • Average High 2021–2026

    66.8 °F
Get WillyWeather+ to remove ads