Chatham Harbor - Tern Island Weather Forecast

    • 61
    • 73

    Chance Rain Showers

    • 53
    • 74

    Mostly Sunny

    • 52
    • 67

    Mostly Sunny

    • 56
    • 67

    Partly Sunny

    • 59
    • 71

    Partly Sunny

    • 60
    • 74

    Partly Sunny

Today 18 Sep Barnstable

Mostly cloudy with a slight chance of Showers and Thunderstorms this Morning, then partly sunny this afternoon. Patchy fog. Highs in the mid 70s. North Winds 5 to 10 Mph. Chance of rain 20 percent.

Tonight 18 Sep Barnstable

Partly cloudy in the Evening, then becoming mostly clear. Patchy fog. Lows in the lower 60s. Southwest Winds 5 to 10 Mph.

Graph Plots Open in Graphs

  • Temperature Forecast NOAA

  • Temperature Real-Time

Chatham Harbor - Tern Island Temperature Statistics

September Temperature

Chatham, Chatham Municipal Airport (1.9 miles)

  • Lowest 13 September, 2025

    46.9 °F

  • Average September

    64.6 °F

  • Highest 6 September, 2025

    79 °F

Climate (2020–Present)

Chatham, Chatham Municipal Airport (1.9 miles)

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

  • Average Low 2020–2025

    47.7 °F

  • Average 2020–2025

    54 °F

  • Average High 2020–2025

    60.1 °F
Get WillyWeather+ to remove ads