September weather forecast
Glastonbury, CT

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Weather in September

September carries the transitional weather from Summer into Fall in Glastonbury. The temperature starts to dip appreciatively from August, experiencing the range of 55.6°F (13.1°C) to 73.4°F (23°C), indicating a shift to cooler days ahead. The trees begin their transformation into breathtaking hues of red and gold. The rainfall level decreases significantly, making way for clear skies and an abundance of outdoor occasions. As the nights become longer, the temperature and humidity level dips intensifying the vibrancy of fall.

Temperature

As August shifts into September in Glastonbury, Connecticut, a minor alteration in temperatures is observed, with average highs reducing from a warm 81°F (27.2°C) to a still moderately hot 73.4°F (23°C). Glastonbury's average low-temperature in the month of September is recorded at a refreshing 55.6°F (13.1°C).

Humidity

The average relative humidity in September is 77%.

Rainfall

September is the month with the least rainfall. Rain falls for 12.8 days and accumulates 1.93" (49mm) of precipitation.

Snowfall

In Glastonbury, Connecticut, snow does not fall in June through October.

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 7:23 pm. On the last day of September, sunrise is at 6:46 am and sunset at 6:33 pm EDT.

Sunshine

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

UV index

The average daily maximum UV index in September in Glastonbury is 4. A UV Index reading of 3 to 5 represents a medium health hazard from exposure to the Sun's UV radiation for ordinary individuals.
Note: A maximum UV index of 4 in September translates into the following recommendations:
Adopt protective measures - Requirement to safeguard skin and eyes from harm exists. Avoiding direct sun during mid-day hours can prevent harmful UV radiation exposure. A hat with a generous brim can prevent nearly 50% of UV rays from reaching your eyes.

Frequently asked questions

What is the average September temperature?

The high-temperature during September is 73.4°F (23°C) and the low-temperature is 55.6°F (13.1°C). The average heat index (a.k.a. 'apparent temperature', 'feels like'), which takes the relative humidity and factors it into the air temperature reading, in August is calculated to be 86°F (30°C).

What is the average humidity in September?

In September, the average relative humidity is 77%.

What is the driest month?

September is the month with the least rainfall. Rain falls for 12.8 days and accumulates 1.93" (49mm) of precipitation.

How many days does it rain in September?

In Glastonbury, in September, during 12.8 rainfall days, 1.93" (49mm) of precipitation is typically accumulated.

When it does not snow in Glastonbury?

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

What is the average length of the day in September?

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

When is the sunrise / sunset in September?

On the first day of September, sunrise is at 6:16 am and sunset at 7:23 pm. On the last day of the month, sunrise is at 6:46 am and sunset at 6:33 pm EDT.

How many hours of sunshine does Glastonbury have in September?

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

What is the UV index reading in September?

In Glastonbury, the average daily maximum UV index in September is 4. A UV Index of 3 to 5 symbolizes a medium health risk 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
Glastonbury, CT

Average temperature in September - Glastonbury, 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 (33.4°F).

  • Average low temperature in September: 55.6°F

The month with the highest average low temperature is July (63.7°F).
The coldest month (with the lowest average low temperature) is January (21.2°F).

Average pressure in September
Glastonbury, CT

Average pressure in September - Glastonbury, 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
Glastonbury, CT

Average wind speed in September - Glastonbury, 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 months (with the lowest average wind speed) are July and August (5.3mph).

Average humidity in September
Glastonbury, CT

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

The month with the highest relative humidity is February (79%).
The month with the lowest relative humidity is April (70%).

Average rainfall in September
Glastonbury, CT

Average rainfall in September - Glastonbury, CT
  • Average rainfall in September: 1.93"

The wettest month (with the highest rainfall) is December (3.19").
The driest month (with the least rainfall) is September (1.93").

Average rainfall days in September
Glastonbury, CT

Average rainfall days in September - Glastonbury, CT
  • Average rainfall days in September: 12.8 days

The month with the highest number of rainy days is July (17.6 days).
The month with the least rainy days is January (9.2 days).

Average snowfall in September
Glastonbury, CT

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

The month with the highest snowfall is February (4.45").
The months with the least snowfall are June, July, August, September and October (0").

Average snowfall days in September
Glastonbury, CT

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

The month with the highest number of snowfall days is February (8.1 days).
The months with the least snowfall days are June, July, August and September (0 days).

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

Average daylight in September / Average sunshine in September - Glastonbury, 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
Glastonbury, CT

Average sunshine days in September - Glastonbury, CT
  • Average sunshine days in September: 13.9 days

The month with the most sunshine days is January (17.6 days).
The month with the least sunshine days is June (10.7 days).

Average UV index in September
Glastonbury, CT

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

The months with the highest UV index are June and July (UV index 6).
The month with the lowest UV index is December (UV index 1).

Average cloud cover in September
Glastonbury, CT

Average cloud cover in September - Glastonbury, CT
  • Average cloud cover in September: 36

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
Glastonbury, CT

Average visibility in September - Glastonbury, 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).

Glastonbury, Connecticut, USA

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