September weather forecast
Bolton, CT

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Grass, brown sand, and trees on an empty beach in Bolton, Connecticut, overlooking the blue waters far out
Grass, brown sand, and trees on an empty beach in Bolton, Connecticut, overlooking the blue waters far out

Weather in September

September in Bolton signifies the start of the much-anticipated fall season. A notable departure from the sweltering summer, this month brings a crisp chill to the air, particularly during the late evenings and early mornings. The cool breeze ushered in this month brings with it fallen leaves, painting the city in warm hues of autumn. While temperatures still touch a reasonable 73.4°F (23°C), September presents the first glimpses of fall, and with it, the promise of a dramatic show of fall foliage.

Temperature

During the shift to September, a minor reduction in average high-temperature is observed, shifting from a moderately hot 81°F (27.2°C) in August to a still warm 73.4°F (23°C). Throughout September, an average nighttime temperature of 55.2°F (12.9°C) is experienced.

Humidity

The average relative humidity in September is 77%.

Rainfall

September is the month with the least rainfall. Rain falls for 12.5 days and accumulates 1.77" (45mm) of precipitation.

Snowfall

In Bolton, snow does not fall in June through September.

Daylight

The average length of the day in September is 12h and 28min.
On the first day of the month, sunrise is at 6:16 am and sunset at 7:22 pm. On the last day of September, in Bolton, sunrise is at 6:46 am and sunset at 6:32 pm EDT.

Sunshine

In September, the average sunshine is 8.7h.

UV index

In September, the average daily maximum UV index is 4. A UV Index value of 3 to 5 symbolizes a medium vulnerability from unsafe exposure to UV radiation for the average person.
Note: In September, the maximum UV index of 4 suggests these recommendations:
Be careful. Light complexion individuals might get burns in fewer than 30 minutes. Stay safe from the Sun's strongest UV rays by limiting exposure during midday. To best shield against UV radiation, choose sun-safe garments and dependable sunglasses.
Updated: Jul 27, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What are September temperatures?

The average high-temperature, in September, in Bolton, is 73.4°F (23°C), while the average low-temperature is 55.2°F (12.9°C). The average heat index (a.k.a. 'apparent temperature', 'felt air temperature'), which represents the influence of relative humidity on air temperature, in August is evaluated at 86°F (30°C).

What is the average humidity in September?

In Bolton, the average relative humidity in September is 77%.

What is the driest month in Bolton?

The month with the least rainfall is September, when the rain falls for 12.5 days and typically collects 1.77" (45mm) of precipitation.

How many days does it rain in September?

In September, the rain falls for 12.5 days. Throughout September, 1.77" (45mm) of precipitation is accumulated.

When it does not snow?

June through September are months without snowfall in Bolton.

Does it snow in September?

In Bolton, in September, it doesn't snow. In October, it regularly snows.

How many hours of daylight does Bolton have in September?

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

When are sunrise and sunset in September in Bolton?

In September, on the first day of the month, sunrise is at 6:16 am and sunset at 7:22 pm. On the last day of the month, sunrise is at 6:46 am and sunset at 6:32 pm EDT.

How many hours of sunshine does Bolton have in September?

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

What is the UV index reading in September?

The average daily maximum UV index in September in Bolton is 4. A UV Index of 3 to 5 symbolizes a medium health risk from 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
Bolton, CT

Average temperature in September - Bolton, CT
  • Average high temperature in September: 73.4°F

The warmest month (with the highest average high temperature) is July (83.1°F).
The month with the lowest average high temperature is January (32.9°F).

  • Average low temperature in September: 55.2°F

The month with the highest average low temperature is July (63.5°F).
The coldest month (with the lowest average low temperature) is January (21.2°F).

Average pressure in September
Bolton, CT

Average pressure in September - Bolton, CT
  • Average pressure in September: 30.06"Hg

The month with the highest atmospheric pressure is November (30.09"Hg).
The month with the lowest atmospheric pressure is June (29.93"Hg).

Average wind speed in September
Bolton, CT

Average wind speed in September - Bolton, CT
  • Average wind speed in September: 5.8mph

The windiest months (with the highest average wind speed) are January and March (8.1mph).
The calmest month (with the lowest average wind speed) is August (5.2mph).

Average humidity in September
Bolton, CT

Average humidity in September - Bolton, CT
  • Average humidity in September: 77%

The month with the highest relative humidity is February (80%).
The month with the lowest relative humidity is April (71%).

Average rainfall in September
Bolton, CT

Average rainfall in September - Bolton, CT
  • Average rainfall in September: 1.77"

The wettest month (with the highest rainfall) is December (3.27").
The driest month (with the least rainfall) is September (1.77").

Average rainfall days in September
Bolton, CT

Average rainfall days in September - Bolton, CT
  • Average rainfall days in September: 12.5 days

The month with the highest number of rainy days is July (17.3 days).
The month with the least rainy days is January (10 days).

Average snowfall in September
Bolton, CT

Average snowfall in September - Bolton, CT
  • Average snowfall in September: 0"

The month with the highest snowfall is February (4.8").
The months with the least snowfall are June, July, August and September (0").

Average snowfall days in September
Bolton, CT

Average snowfall days in September - Bolton, CT
  • Average snowfall days in September: 0 days

The month with the highest number of snowfall days is February (8.5 days).
The months with the least snowfall days are June, July, August and September (0 days).

Average daylight in September /
Average sunshine in September
Bolton, CT

Average daylight in September / Average sunshine in September - Bolton, CT
  • 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 4min

The months with the most sunshine are July and August (Average sunshine: 10h and 24min).
The month with the least sunshine is February (Average sunshine: 4h and 36min).

Average sunshine days in September
Bolton, CT

Average sunshine days in September - Bolton, CT
  • Average sunshine days in September: 14.6 days

The month with the most sunshine days is November (17.2 days).
The month with the least sunshine days is June (11.2 days).

Average UV index in September
Bolton, CT

Average UV index in September - Bolton, CT
  • Average UV index in September: 4

The months with the highest UV index are June and July (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
Bolton, CT

Average cloud cover in September - Bolton, CT
  • Average cloud cover in September: 37

The month with the most cloud cover is February (Cloud cover 49).
The month with the least cloud cover is August (Cloud cover 33).

Average visibility in September
Bolton, CT

Average visibility in September - Bolton, CT
  • Average visibility in September: 5mi

The months with the highest visibility are January, March, April, June, July, August, October, November and December (6mi).
The months with the lowest visibility are February, May and September (5mi).

Bolton, Connecticut, USA

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