September weather forecast
Harwich Port, MA

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Weather in September

The first month of the autumn, September, is still a refreshing month in Harwich Port, Massachusetts, with an average temperature fluctuating between 63.3°F (17.4°C) and 66.6°F (19.2°C).

Temperature

The onset of September brings an average high-temperature of a comfortable 66.6°F (19.2°C), nearly matching the August temperature. Harwich Port nights in September witness a mild cool down to an average temperature of 63.3°F (17.4°C).

Humidity

In September, the average relative humidity is 80%.

Rainfall

In Harwich Port, in September, it is raining for 10.7 days, with typically 1.85" (47mm) of accumulated precipitation. Throughout the year, there are 142.4 rainfall days, and 22.09" (561mm) of precipitation is accumulated.

Snowfall

May through October are months without snowfall.

Ocean temperature

In Harwich Port, in September, the average water temperature is 64.2°F (17.9°C).
Note: For most people, swimming in water at 64.2°F (17.9°C) is not a pleasurable experience. Breathing control gets harder as the water temperature descends from 69.8°F (21°C) to 59°F (15°C).

Daylight

The average length of the day in September is 12h and 28min.
On the first day of September, sunrise is at 6:06 am and sunset at 7:13 pm. On the last day of the month, sunrise is at 6:36 am and sunset at 6:23 pm EDT.

Sunshine

In September, the average sunshine is 8.5h.

UV index

In September, the average daily maximum UV index is 4. A UV Index of 3 to 5 symbolizes a moderate threat to health from exposure to the Sun's UV radiation for the average person.
Note: A daily high UV index of 4 in September leads to these guidelines:
Adopt protective measures - Suggestions to resist sunburn are offered. To protect against the Sun's most potent rays, avoid direct exposure around midday. To best shield against UV radiation, choose sun-safe garments and dependable sunglasses.

Frequently asked questions

What are the temperatures in September?

In September, the average high-temperature and low-temperature are 66.6°F (19.2°C) and 63.3°F (17.4°C) respectively.

What is the average humidity in September?

The average relative humidity in September in Harwich Port is 80%.

How many days does it rain in September?

In Harwich Port, in September, during 10.7 rainfall days, 1.85" (47mm) of precipitation is typically accumulated.

When it does not snow?

May through October are months without snowfall in Harwich Port.

What is the ocean temperature in September in Harwich Port?

In Harwich Port, the average seawater temperature in September is 64.2°F (17.9°C). For most, swimming in 64.2°F (17.9°C) is not an enjoyable activity. Furthermore, controlling your breathing becomes progressively more difficult as the water temperature decreases from 69.8°F (21°C) to 59°F (15°C).

How many hours of daylight does Harwich Port have in September?

In Harwich Port, the average day length in September is 12h and 28min.

When is the sunrise / sunset in September in Harwich Port?

In September, on the first day of the month, sunrise is at 6:06 am and sunset at 7:13 pm. On the last day of the month, sunrise is at 6:36 am and sunset at 6:23 pm EDT.

How many hours of sunshine does Harwich Port have in September?

The average sunshine duration in September in Harwich Port is 8.5h.

What is the UV index reading in September?

In Harwich Port, the average daily maximum UV index in September is 4. A UV Index of 3 to 5 symbolizes a medium hazard to health from exposure to the Sun's UV radiation.
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
Harwich Port, MA

Average temperature in September - Harwich Port, MA
  • Average high temperature in September: 66.6°F

The warmest month (with the highest average high temperature) is August (71.6°F).
The months with the lowest average high temperature are January and February (39°F).

  • Average low temperature in September: 63.3°F

The month with the highest average low temperature is August (68.2°F).
The coldest month (with the lowest average low temperature) is January (31.6°F).

Average pressure in September
Harwich Port, MA

Average pressure in September - Harwich Port, 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 (29.93"Hg).

Average wind speed in September
Harwich Port, MA

Average wind speed in September - Harwich Port, MA
  • Average wind speed in September: 13.5mph

The windiest month (with the highest average wind speed) is January (18mph).
The calmest month (with the lowest average wind speed) is August (11.4mph).

Average humidity in September
Harwich Port, MA

Average humidity in September - Harwich Port, MA
  • Average humidity in September: 80%

The months with the highest relative humidity are June and July (85%).
The month with the lowest relative humidity is November (74%).

Average rainfall in September
Harwich Port, MA

Average rainfall in September - Harwich Port, MA
  • Average rainfall in September: 1.85"

The wettest month (with the highest rainfall) is October (2.83").
The driest month (with the least rainfall) is November (1.46").

Average rainfall days in September
Harwich Port, MA

Average rainfall days in September - Harwich Port, MA
  • Average rainfall days in September: 10.7 days

The month with the highest number of rainy days is May (14.6 days).
The month with the least rainy days is February (8.3 days).

Average snowfall in September
Harwich Port, MA

Average snowfall in September - Harwich Port, MA
  • Average snowfall in September: 0"

The month with the highest snowfall is February (1.38").
The months with the least snowfall are May, June, July, August, September and October (0").

Average snowfall days in September
Harwich Port, MA

Average snowfall days in September - Harwich Port, MA
  • Average snowfall days in September: 0 days

The month with the highest number of snowfall days is January (6 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).

Average sea temperature in September
Harwich Port, MA

Average sea temperature in September - Harwich Port, MA
  • Average sea temperature in September: 64.3°F

The best month for swimming (with the highest average sea temperature) is August (67.5°F).
The coldest month (with the lowest average sea temperature) is March (39°F).

Average daylight in September /
Average sunshine in September
Harwich Port, MA

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

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 3min

The month with the most sunshine is August (Average sunshine: 10h and 42min).
The month with the least sunshine is December (Average sunshine: 4h and 18min).

Average sunshine days in September
Harwich Port, MA

Average sunshine days in September - Harwich Port, MA
  • Average sunshine days in September: 16.9 days

The month with the most sunshine days is August (17.6 days).
The month with the least sunshine days is January (13 days).

Average UV index in September
Harwich Port, MA

Average UV index in September - Harwich Port, MA
  • Average UV index in September: 4

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
Harwich Port, MA

Average cloud cover in September - Harwich Port, MA
  • Average cloud cover in September: 32

The month with the most cloud cover is December (Cloud cover 54).
The month with the least cloud cover is August (Cloud cover 27).

Average visibility in September
Harwich Port, MA

Average visibility in September - Harwich Port, 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).

Harwich Port, Massachusetts, USA

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