September weather forecast
Swansea, MA

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Weather in September

The first month of the autumn, September, is also an agreeable month in Swansea, Massachusetts, with an average temperature ranging between max 72.1°F (22.3°C) and min 58.8°F (14.9°C).

Temperature

September heralds a minor drop in average high-temperature, sliding from August's moderately hot 78.6°F (25.9°C) to an agreeable 72.1°F (22.3°C). In September, Swansea experiences a temperature dip to an average of 58.8°F (14.9°C) at night.

Humidity

The average relative humidity in September is 78%.

Rainfall

September is the month with the least rainfall. Rain falls for 11.2 days and accumulates 1.06" (27mm) of precipitation.

Snowfall

In Swansea, snow does not fall in June through October.

Daylight

In Swansea, the average length of the day in September is 12h and 28min.
On the first day of the month, sunrise is at 6:11 am and sunset at 7:17 pm. On the last day of September, sunrise is at 6:41 am and sunset at 6:27 pm EDT.

Sunshine

The average sunshine in September is 8.8h.

UV index

The average daily maximum UV index in September in Swansea, Massachusetts, is 4. A UV Index reading of 3 to 5 represents a moderate health risk from exposure to the Sun's UV radiation for ordinary individuals.
Note: In September, the maximum UV index of 4 transforms into these recommendations:
Be vigilant - Suggestions to stave off sun damage are provided. To prevent harmful UV exposure, minimize direct contact with the Sun around midday. Consider a wide-brim hat essential for effective sun defense covering your face, neck, and eyes.
Updated: Aug 21, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What are the temperatures in September?

In Swansea, 72.1°F (22.3°C) is the average high-temperature and 58.8°F (14.9°C) is the average low-temperature during September.

What is the average humidity in September?

In September, the average relative humidity is 78%.

What is the driest month in Swansea?

The month with the least rainfall is September, when the rain falls for 11.2 days and typically collects 1.06" (27mm) of precipitation.

How many days does it rain in September in Swansea?

In September, the rain falls for 11.2 days. Throughout September, 1.06" (27mm) of precipitation is accumulated.

When it does not snow?

June through October are months without snowfall in Swansea.

What is the average length of the day in September?

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

What time are sunrise and sunset in September?

In September, on the first day of the month, sunrise is at 6:11 am and sunset at 7:17 pm. On the last day of the month, sunrise is at 6:41 am and sunset at 6:27 pm EDT.

How long on average sun shines in September?

In Swansea, the average sunshine duration in September is 8.8h.

What is the UV index reading in September?

In September, the average daily maximum UV index is 4. A UV Index of 3 to 5 symbolizes a medium health risk from unprotected exposure to 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
Swansea, MA

Average temperature in September - Swansea, MA
  • Average high temperature in September: 72.1°F

The warmest month (with the highest average high temperature) is July (79.3°F).
The month with the lowest average high temperature is January (36°F).

  • Average low temperature in September: 58.8°F

The month with the highest average low temperature is July (65.5°F).
The coldest month (with the lowest average low temperature) is January (25.2°F).

Average pressure in September
Swansea, MA

Average pressure in September - Swansea, 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
Swansea, MA

Average wind speed in September - Swansea, MA
  • Average wind speed in September: 8.2mph

The windiest months (with the highest average wind speed) are January, February and March (10.9mph).
The calmest month (with the lowest average wind speed) is August (7.3mph).

Average humidity in September
Swansea, MA

Average humidity in September - Swansea, MA
  • Average humidity in September: 78%

The month with the highest relative humidity is June (80%).
The month with the lowest relative humidity is April (73%).

Average rainfall in September
Swansea, MA

Average rainfall in September - Swansea, MA
  • Average rainfall in September: 1.06"

The wettest month (with the highest rainfall) is October (1.97").
The driest month (with the least rainfall) is September (1.06").

Average rainfall days in September
Swansea, MA

Average rainfall days in September - Swansea, MA
  • Average rainfall days in September: 11.2 days

The month with the highest number of rainy days is July (15 days).
The month with the least rainy days is February (6.9 days).

Average snowfall in September
Swansea, MA

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

The month with the highest snowfall is March (2.13").
The months with the least snowfall are June, July, August, September and October (0").

Average snowfall days in September
Swansea, MA

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

The month with the highest number of snowfall days is January (5.9 days).
The months with the least snowfall days are June, July, August, September and October (0 days).

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

Average daylight in September / Average sunshine in September - Swansea, 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 5min

The month with the most sunshine is August (Average sunshine: 10h and 36min).
The months with the least sunshine are February and December (Average sunshine: 4h and 54min).

Average sunshine days in September
Swansea, MA

Average sunshine days in September - Swansea, MA
  • Average sunshine days in September: 15.9 days

The month with the most sunshine days is November (19.2 days).
The month with the least sunshine days is April (13.6 days).

Average UV index in September
Swansea, MA

Average UV index in September - Swansea, 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 and December (UV index 2).

Average cloud cover in September
Swansea, MA

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

The month with the most cloud cover is March (Cloud cover 48).
The month with the least cloud cover is August (Cloud cover 29).

Average visibility in September
Swansea, MA

Average visibility in September - Swansea, 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).

Swansea, Massachusetts, USA

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