September weather forecastMattapoisett, MA
September
Weather in September
The first month of the autumn, September, is also an agreeable month in Mattapoisett, Massachusetts, with an average temperature varying between 71.2°F (21.8°C) and 59.7°F (15.4°C).Temperature
September heralds a minor drop in average high-temperature, sliding from August's moderately hot 78.3°F (25.7°C) to a pleasant 71.2°F (21.8°C). In Mattapoisett, the September nights cool down to an average low of 59.7°F (15.4°C).Humidity
The average relative humidity in September is 78%.Rainfall
September is the month with the least rainfall. Rain falls for 10.5 days and accumulates 1.06" (27mm) of precipitation.Snowfall
In Mattapoisett, snow does not fall in May through October.Ocean temperature
In September, the average ocean temperature is 65.8°F (18.8°C).Note: In water with a temperature of 65.8°F (18.8°C), most people do not enjoy swimming. As the temperature descends from 69.8°F (21°C) to 59°F (15°C), breathing becomes increasingly difficult to control.
Daylight
In Mattapoisett, the average length of the day in September is 12h and 28min.On the first day of the month, sunrise is at 6:09 am and sunset at 7:16 pm. On the last day of September, sunrise is at 6:39 am and sunset at 6:26 pm EDT.
Sunshine
In September, the average sunshine is 8.7h.UV index
The average daily maximum UV index in September is 4. A UV Index of 3 to 5 symbolizes a medium health hazard from unprotected exposure to Sun's UV rays for average individuals.Note: The maximum daily UV index, 4 in September, converts into the following recommendations:
Take precautions - Protection against sunburn is recommended. The midday Sun can be harmful due to its potent UV radiation; seek shade and reduce exposure. Outfit yourself in sun-safe attire, like long sleeves, pants, a hat, and UV-blocking sunglasses.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Mattapoisett, MA
- Average high temperature in September: 71.2°F
The warmest month (with the highest average high temperature) is July (78.4°F).
The month with the lowest average high temperature is January (36.3°F).
- Average low temperature in September: 59.7°F
The month with the highest average low temperature is July (66.4°F).
The coldest month (with the lowest average low temperature) is January (26.8°F).
Average pressure in September
Mattapoisett, MA
- Average pressure in September: 30.05"Hg
The month with the highest atmospheric pressure is November (30.07"Hg).
The month with the lowest atmospheric pressure is June (29.93"Hg).
Average wind speed in September
Mattapoisett, MA
- Average wind speed in September: 9mph
The windiest month (with the highest average wind speed) is January (11.9mph).
The calmest month (with the lowest average wind speed) is August (8mph).
Average humidity in September
Mattapoisett, MA
- Average humidity in September: 78%
The months with the highest relative humidity are June and July (80%).
The months with the lowest relative humidity are March, April and November (74%).
Average rainfall in September
Mattapoisett, MA
- Average rainfall in September: 1.06"
The wettest month (with the highest rainfall) is October (1.93").
The driest month (with the least rainfall) is September (1.06").
Average rainfall days in September
Mattapoisett, MA
- Average rainfall days in September: 10.5 days
The month with the highest number of rainy days is July (13.4 days).
The month with the least rainy days is January (8.2 days).
Average snowfall in September
Mattapoisett, MA
- Average snowfall in September: 0"
The month with the highest snowfall is February (1.77").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in September
Mattapoisett, MA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (6.5 days).
The months with the least snowfall days are June, July, August, September and October (0 days).
Average sea temperature in September
Mattapoisett, MA
- Average sea temperature in September: 65.8°F
The best month for swimming (with the highest average sea temperature) is August (68.4°F).
The coldest month (with the lowest average sea temperature) is February (38.2°F).
Average daylight in September /
Average sunshine in September
Mattapoisett, MA
- Average daylight in September: 12h and 30min
The month with the longest days is June (Average daylight: 15h and 12min).
The month with the shortest days is December (Average daylight: 9h and 12min).
- Average sunshine in September: 8h and 42min
The month with the most sunshine is August (Average sunshine: 10h and 36min).
The month with the least sunshine is February (Average sunshine: 4h and 48min).
Average sunshine days in September
Mattapoisett, MA
- Average sunshine days in September: 16.7 days
The months with the most sunshine days are November and December (18.3 days).
The month with the least sunshine days is April (14.4 days).
Average UV index in September
Mattapoisett, MA
- Average UV index in September: 4
The months with the highest UV index are June, July and August (UV index 6).
The months with the lowest UV index are January, February, March, November and December (UV index 2).
Average cloud cover in September
Mattapoisett, MA
- Average cloud cover in September: 32
The month with the most cloud cover is March (Cloud cover 49).
The month with the least cloud cover is August (Cloud cover 28).
Average visibility in September
Mattapoisett, MA
- Average visibility in September: 6mi
The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
