Brunswick Weather in September

What's the weather like in Brunswick (Maine) in September 2025?

The climate in Brunswick during September can be summarized as mild and reasonably dry.

September is in the fall / autumn in Brunswick and is typically the 4th warmest month of the year. Daytime maximum temperatures average around 21°C (70°F), whilst at night 10°C (50°F) is normal.

Brunswick weather averages (imperial / metric)
Daytime temperature 21.3°C 70.3°F
Nightly temperature 10.1°C 50.2°F
Average temperature 15.7°C 60.3°F
Daily sunshine 7.7 hrs
Avg rainfall 78 mm 3.1 ins
Rainy days 9 days
Sea temperature 14.8°C 58.7°F
Humidity 78%
Windspeed 12.6kph 8 mph

On average September is the 2nd driest month of the year in Brunswick with around 78mm 3.1 inches of rain making it a reasonably dry time to visit. This rainfall is typically spread over 9 days, although this may vary considerably.

On the flip side this corresponds to an average of 7.7 hours of sunshine per day.

September temperatures in Brunswick

Brunswick average temperature in September

September rainfall

Brunswick average rain in September

September hourly sunshine

Brunswick 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 Brunswick 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

Brunswick weather stats

Brunswick weather statistics
Hottest month: July 26.2°C 79.2°F
Driest month: July 76mm 3ins
Sunniest month: August 8.8hrs
Coldest month: January -0.7°C 30.7°F
Wettest month: November 123mm 4.8ins
Map showing location of Brunswick (43.91452, -69.96533) Brunswick map pin © Google

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