Portsmouth Weather in September

What's the weather like in Portsmouth (Saint John) in September 2023?

The climate in Portsmouth during September can be summarized as hot, humid and very wet.

September is in the fall / autumn in Portsmouth and is typically the 3rd warmest month of the year. Daytime maximum temperatures average around a steamy 31°C (88°F), whilst at night 24°C (74°F) is normal.

Portsmouth weather averages (imperial / metric)
Daytime temperature 31°C 87.7°F
Nightly temperature 23.5°C 74.2°F
Average temperature 27.2°C 81°F
Daily sunshine 7.6 hrs
Avg rainfall 269 mm 10.6 ins
Rainy days 22 days
Sea temperature 29°C 84.2°F
Humidity 81%
Windspeed 14.8kph 9 mph

On average September is the 3rd wettest month of the year in Portsmouth with around 269mm 10.6 inches of rain making it a very wet time to visit. This rainfall is typically spread over 22 days, although this may vary considerably.

On the flip side this corresponds to an average of 7.6 hours of sunshine per day.

September temperatures in Portsmouth

Portsmouth average temperature in September

September rainfall

Portsmouth average rain in September

September hourly sunshine

Portsmouth 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 Portsmouth in September 2023.

Other monthly averages

Best places to visit in September

UV index Best time to go?

Portsmouth weather stats

Portsmouth weather statistics
Hottest month: July 30.6°C 87.1°F
Driest month: February 95mm 3.7ins
Sunniest month: April 8.6hrs
Coldest month: February 28.3°C 82.9°F
Wettest month: November 301mm 11.9ins
Map showing location of Portsmouth (15.58333, -61.46667)

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