Barnstable Weather in September

What's the weather like in Barnstable (Massachusetts) in September 2025?

The climate in Barnstable during September can be summarized as mild and a little damp.

September is in the fall / autumn in Barnstable and is typically the 4th warmest month of the year. Daytime maximum temperatures average around 21°C (70°F), whilst at night 13°C (56°F) is normal.

Barnstable weather averages (imperial / metric)
Daytime temperature 21.2°C 70.1°F
Nightly temperature 13.3°C 55.9°F
Average temperature 17.2°C 63°F
Daily sunshine 8.2 hrs
Avg rainfall 87 mm 3.4 ins
Rainy days 8 days
Sea temperature 18.4°C 65.2°F
Humidity 75%
Windspeed 15.1kph 9 mph

On average September is the 4th driest month of the year in Barnstable with around 87mm 3.4 inches of rain making it a a little damp time to visit. This rainfall is typically spread over 8 days, although this may vary considerably.

On the flip side this corresponds to an average of 8.2 hours of sunshine per day.

September temperatures in Barnstable

Barnstable average temperature in September

September rainfall

Barnstable average rain in September

September hourly sunshine

Barnstable average rain in September

The data used in these monthly averages covers a period of over 100 years right up until last year. As such they are a valid prediction of what to expect for the weather in Barnstable in September 2025.

Other monthly averages

Best places to visit in September

UV index Best time to go?

Beta

Current (hourly) weather 15 day forecast

Barnstable weather stats

Barnstable weather statistics
Hottest month: July 25.2°C 77.4°F
Driest month: July 68mm 2.7ins
Sunniest month: September 8.2hrs
Coldest month: January 2.4°C 36.3°F
Wettest month: November 116mm 4.6ins
Map showing location of Barnstable (41.70011, -70.29947) Barnstable map pin © Google

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