September weather forecast
Edgartown, MA

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Classy and luxurious houses right on the harbor in Edgartown, Massachusetts, with long piers onto the water
Classy and luxurious houses right on the harbor in Edgartown, Massachusetts, with long piers onto the water

Weather in September

In September, Edgartown starts to cool off as autumn sets in, with temperature averages sliding from 63.7°F (17.6°C) to 68.2°F (20.1°C). This month has a rainfall measurement of 1.85" (47mm). As fall approaches, the winds pick up pace, lending a crispness to the air. However, the sea remains warm enough for swimming with temperatures still enjoyable. With its mild weather and beautiful autumn colors, September is truly picturesque.

Temperature

The transition to September results in a modest reduction in average high-temperature, moving from a moderately hot 73.9°F (23.3°C) in August to an agreeable 68.2°F (20.1°C). Throughout September, Edgartown's nights experience a slight temperature dip to an enjoyable 63.7°F (17.6°C).

Humidity

In Edgartown, the average relative humidity in September is 79%.

Rainfall

In Edgartown, during September, the rain falls for 11.4 days and regularly aggregates up to 1.85" (47mm) of precipitation. In Edgartown, during the entire year, the rain falls for 146.4 days and collects up to 25.47" (647mm) of precipitation.

Snowfall

In Edgartown, snow does not fall in April through November.

Ocean temperature

In Edgartown, in September, the average water temperature is 66.4°F (19.1°C).
Note: For most, swimming in 66.4°F (19.1°C) is not a pleasant experience. As the temperature falls from 69.8°F (21°C) to 59°F (15°C), controlling one's breathing becomes more difficult.

Daylight

The average length of the day in September is 12h and 28min.
On the first day of September, sunrise is at 6:09 am and sunset at 7:14 pm. On the last day of the month, sunrise is at 6:38 am and sunset at 6:25 pm EDT.

Sunshine

In Edgartown, the average sunshine in September is 8.7h.

UV index

In September, the average daily maximum UV index is 5. A UV Index estimate of 3 to 5 represents a medium vulnerability from unprotected exposure to Sun's UV rays for the average person.
Note: In September, the maximum UV index of 5 suggests this advice:
Make use of precautions - Suggestions to resist sunburn are communicated. The midday Sun can be harmful due to its potent UV radiation; seek shade and reduce exposure. Wearing a wide-brim hat can block approximately 50% of UV radiation, protecting the eyes.
Updated: Aug 13, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What is the temperature in September?

In Edgartown, 68.2°F (20.1°C) is the average high-temperature and 63.7°F (17.6°C) is the average low-temperature during September.

What is the average humidity in September?

The average relative humidity in September is 79%.

How many days does it rain in September?

In Edgartown, Massachusetts, during September, the rain falls for 11.4 days and regularly aggregates up to 1.85" (47mm) of precipitation.

When it does not snow?

In Edgartown, snow does not fall in April through November.

How cold is the water in September?

In Edgartown, the average seawater temperature in September is 66.4°F (19.1°C). Swimming in 66.4°F (19.1°C) is not enjoyable for the majority. Controlling breathing becomes progressively more difficult as surface water temperature decreases below 69.8°F (21°C).

How many hours of daylight does Edgartown have in September?

The average day length in September is 12h and 28min.

When is the sunrise / sunset in September?

In September, on the first day of the month, sunrise is at 6:09 am and sunset at 7:14 pm. On the last day of the month, sunrise is at 6:38 am and sunset at 6:25 pm EDT.

How many hours of sunshine does Edgartown have in September?

In September, the average sunshine duration in Edgartown is 8.7h.

How high is the UV index in September?

The average daily maximum UV index in September is 5. A UV Index of 3 to 5 symbolizes a medium hazard to health from unsafe exposure to Sun's UV rays.
Average humidity
Average rainfall days
Average snowfall
Average snowfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in September
Edgartown, MA

Average temperature in September - Edgartown, MA
  • Average high temperature in September: 68.2°F

The warmest month (with the highest average high temperature) is August (73.9°F).
The month with the lowest average high temperature is January (38.7°F).

  • Average low temperature in September: 63.7°F

The month with the highest average low temperature is August (69.4°F).
The coldest month (with the lowest average low temperature) is January (30.6°F).

Average pressure in September
Edgartown, MA

Average pressure in September - Edgartown, MA
  • Average pressure in September: 30.05"Hg

The month with the highest atmospheric pressure is November (30.06"Hg).
The month with the lowest atmospheric pressure is June (29.94"Hg).

Average wind speed in September
Edgartown, MA

Average wind speed in September - Edgartown, MA
  • Average wind speed in September: 12.6mph

The windiest month (with the highest average wind speed) is January (16.2mph).
The calmest months (with the lowest average wind speed) are July and August (10.9mph).

Average humidity in September
Edgartown, MA

Average humidity in September - Edgartown, MA
  • Average humidity in September: 79%

The months with the highest relative humidity are May, June and July (83%).
The month with the lowest relative humidity is November (74%).

Average rainfall in September
Edgartown, MA

Average rainfall in September - Edgartown, MA
  • Average rainfall in September: 1.85"

The wettest month (with the highest rainfall) is October (3.07").
The driest months (with the least rainfall) are August and November (1.73").

Average rainfall days in September
Edgartown, MA

Average rainfall days in September - Edgartown, MA
  • Average rainfall days in September: 11.4 days

The month with the highest number of rainy days is April (14.5 days).
The month with the least rainy days is February (8.6 days).

Average snowfall in September
Edgartown, MA

Average snowfall in September - Edgartown, MA
  • Average snowfall in September: 0"

The month with the highest snowfall is March (1.18").
The months with the least snowfall are April, May, June, July, August, September, October and November (0").

Average snowfall days in September
Edgartown, MA

Average snowfall days in September - Edgartown, MA
  • Average snowfall days in September: 0 days

The month with the highest number of snowfall days is January (5.3 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).

Average sea temperature in September
Edgartown, MA

Average sea temperature in September - Edgartown, MA
  • Average sea temperature in September: 66.4°F

The best month for swimming (with the highest average sea temperature) is August (68.5°F).
The coldest month (with the lowest average sea temperature) is February (37.9°F).

Average daylight in September /
Average sunshine in September
Edgartown, MA

Average daylight in September / Average sunshine in September - Edgartown, MA
  • Average daylight in September: 12h and 3min

The month with the longest days is June (Average daylight: 15h and 6min).
The month with the shortest days is December (Average daylight: 9h and 12min).

  • Average sunshine in September: 8h and 4min

The month with the most sunshine is August (Average sunshine: 10h and 42min).
The month with the least sunshine is February (Average sunshine: 4h and 42min).

Average sunshine days in September
Edgartown, MA

Average sunshine days in September - Edgartown, MA
  • Average sunshine days in September: 16.2 days

The month with the most sunshine days is November (16.7 days).
The month with the least sunshine days is April (13.5 days).

Average UV index in September
Edgartown, MA

Average UV index in September - Edgartown, MA
  • Average UV index in September: 5

The months with the highest UV index are 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
Edgartown, MA

Average cloud cover in September - Edgartown, MA
  • Average cloud cover in September: 32

The month with the most cloud cover is December (Cloud cover 50).
The month with the least cloud cover is August (Cloud cover 27).

Average visibility in September
Edgartown, MA

Average visibility in September - Edgartown, 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).

Edgartown, Massachusetts, USA

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