September weather forecast
South Windham, CT

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Weather in September

The first month of the autumn, September, is also an agreeable month in South Windham, Connecticut, with an average temperature varying between 55.4°F (13°C) and 73.2°F (22.9°C).

Temperature

The arrival of September signals a subtle shift in temperature, down from a warm 80.2°F (26.8°C) in August to an agreeable 73.2°F (22.9°C). September brings with it a nighttime average temperature of 55.4°F (13°C).

Humidity

In South Windham, the average relative humidity in September is 78%.

Rainfall

The month with the least rainfall is September, when the rain falls for 13.5 days and typically collects 1.73" (44mm) of precipitation.

Snowfall

In South Windham, snow does not fall in June through October.

Daylight

In September, the average length of the day is 12h and 28min.
On the first day of the month, sunrise is at 6:15 am and sunset at 7:21 pm. On the last day of September, sunrise is at 6:45 am and sunset at 6:31 pm EDT.

Sunshine

The average sunshine in September in South Windham is 8.6h.

UV index

In South Windham, the average daily maximum UV index in September is 4. A UV Index estimate of 3 to 5 represents a moderate threat to health from unsafe exposure to UV radiation for ordinary individuals.
Note: A typical high UV index of 4 in September suggests the following recommendations:
Take precautions - Protection against sunburn is recommended. The Sun's most intense and consequently most harmful UV radiation during midday hours should be decreased by minimizing exposure and seeking shade. Sun-protective clothing, a long-sleeved shirt and pants, a wide-brimmed hat, and UVA and UVB-blocking sunglasses are particularly helpful in blocking UV radiation's harmful effects.
Updated: Aug 17, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What are September temperatures?

September temperatures vary between a high-temperature of 73.2°F (22.9°C) and a low-temperature of 55.4°F (13°C). The average heat index (a.k.a. 'real feel', 'feels like'), which factors the actual air temperature with the relative humidity, in July is estimated at 87.8°F (31°C).

What is the average humidity in September in South Windham?

In South Windham, the average relative humidity in September is 78%.

What is the driest month?

The month with the least rainfall in South Windham is September, when the rain falls for 13.5 days and typically collects 1.73" (44mm) of precipitation.

How much does it rain in September?

In South Windham, during September, the rain falls for 13.5 days and regularly aggregates up to 1.73" (44mm) of precipitation.

When it does not snow?

June through October are months without snowfall.

How many hours of daylight does South Windham have in September?

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

When are sunrise and sunset in September?

In September, on the first day of the month, sunrise is at 6:15 am and sunset at 7:21 pm. On the last day of the month, sunrise is at 6:45 am and sunset at 6:31 pm EDT.

How long on average sun shines in September in South Windham?

In September, the average sunshine duration in South Windham is 8.6h.

How high is the UV index in September?

The average daily maximum UV index in September is 4. A UV Index reading of 3 to 5 represents a moderate vulnerability 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
South Windham, CT

Average temperature in September - South Windham, CT
  • Average high temperature in September: 73.2°F

The warmest month (with the highest average high temperature) is July (81.9°F).
The month with the lowest average high temperature is January (33.4°F).

  • Average low temperature in September: 55.4°F

The month with the highest average low temperature is July (63°F).
The coldest month (with the lowest average low temperature) is January (21.6°F).

Average pressure in September
South Windham, CT

Average pressure in September - South Windham, CT
  • Average pressure in September: 30.05"Hg

The month with the highest atmospheric pressure is November (30.08"Hg).
The month with the lowest atmospheric pressure is June (29.93"Hg).

Average wind speed in September
South Windham, CT

Average wind speed in September - South Windham, CT
  • Average wind speed in September: 6.2mph

The windiest months (with the highest average wind speed) are January and March (8.8mph).
The calmest month (with the lowest average wind speed) is August (5.6mph).

Average humidity in September
South Windham, CT

Average humidity in September - South Windham, CT
  • Average humidity in September: 78%

The months with the highest relative humidity are February and October (79%).
The month with the lowest relative humidity is April (72%).

Average rainfall in September
South Windham, CT

Average rainfall in September - South Windham, CT
  • Average rainfall in September: 1.73"

The wettest month (with the highest rainfall) is December (3.46").
The driest month (with the least rainfall) is September (1.73").

Average rainfall days in September
South Windham, CT

Average rainfall days in September - South Windham, CT
  • Average rainfall days in September: 13.5 days

The month with the highest number of rainy days is May (17.1 days).
The month with the least rainy days is January (9.1 days).

Average snowfall in September
South Windham, CT

Average snowfall in September - South Windham, CT
  • Average snowfall in September: 0"

The month with the highest snowfall is March (4.41").
The months with the least snowfall are June, July, August, September and October (0").

Average snowfall days in September
South Windham, CT

Average snowfall days in September - South Windham, CT
  • Average snowfall days in September: 0 days

The month with the highest number of snowfall days is January (8.3 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
South Windham, CT

Average daylight in September / Average sunshine in September - South Windham, 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 month with the most sunshine is August (Average sunshine: 10h and 18min).
The month with the least sunshine is December (Average sunshine: 4h and 42min).

Average sunshine days in September
South Windham, CT

Average sunshine days in September - South Windham, 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 (10.8 days).

Average UV index in September
South Windham, CT

Average UV index in September - South Windham, CT
  • 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, November and December (UV index 2).

Average cloud cover in September
South Windham, CT

Average cloud cover in September - South Windham, CT
  • Average cloud cover in September: 37

The months with the most cloud cover are February, March, May and December (Cloud cover 48).
The month with the least cloud cover is August (Cloud cover 33).

Average visibility in September
South Windham, CT

Average visibility in September - South Windham, CT
  • Average visibility in September: 5mi

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

South Windham, Connecticut, USA

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