September weather forecast
West Cornwall, CT

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Weather in September

September, the first month of the autumn in West Cornwall, is still a pleasant month, with an average temperature fluctuating between 53.4°F (11.9°C) and 72°F (22.2°C).

Temperature

The average high-temperature shows a slight dip in September, from August's warm 79.2°F (26.2°C) to a pleasant 72°F (22.2°C). West Cornwall's temperature in September lowers to a consistent average of 53.4°F (11.9°C) during the nights.

Humidity

In September, the average relative humidity in West Cornwall is 80%.

Rainfall

In September, in West Cornwall, the rain falls for 13.5 days. Throughout September, 2.24" (57mm) of precipitation is accumulated. Throughout the year, there are 160.5 rainfall days, and 33.86" (860mm) of precipitation is accumulated.

Snowfall

In West Cornwall, Connecticut, snow does not fall in June through September.

Daylight

In West Cornwall, Connecticut, the average length of the day in September is 12h and 28min.
On the first day of September, sunrise is at 6:19 am and sunset at 7:26 pm. On the last day of the month, sunrise is at 6:50 am and sunset at 6:36 pm EDT.

Sunshine

In September, the average sunshine is 8.5h.

UV index

In September, the average daily maximum UV index in West Cornwall is 4. A UV Index estimate of 3 to 5 represents a moderate health risk from unprotected exposure to Sun's UV rays for the ordinary person.
Note: A daily maximum UV index of 4 in September translates into the following instructions:
Undertake protective steps - Recommendations to avoid sunburn are issued. Avoiding the Sun during its peak radiation time around midday is a healthy practice. Employ a hat with a wide brim for robust protection, cutting UV exposure by half.
Updated: Feb 10, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What is the usual temperature for West Cornwall in September?

The average high-temperature, in September, in West Cornwall, is 72°F (22.2°C), while the average low-temperature is 53.4°F (11.9°C). In July, the average heat index (a.k.a. 'apparent temperature', 'felt air temperature'), which combines relative humidity and air temperature, is computed to be 86°F (30°C).

What is the average humidity in September in West Cornwall?

In September, the average relative humidity in West Cornwall, Connecticut, is 80%.

How much does it rain in West Cornwall in September?

In September, in West Cornwall, the rain falls for 13.5 days. Throughout September, 2.24" (57mm) of precipitation is accumulated.

When it does not snow in West Cornwall?

In West Cornwall, Connecticut, snow does not fall in June through September.

Does it snow in West Cornwall in September?

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

What is the average length of the day in September in West Cornwall?

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

When are sunrise and sunset in September in West Cornwall?

In September, on the first day of the month, sunrise is at 6:19 am and sunset at 7:26 pm. On the last day of the month, in West Cornwall, sunrise is at 6:50 am and sunset at 6:36 pm EDT.

How many hours of sunshine does West Cornwall have in September?

The average sunshine duration in September is 8.5h.

What is the UV index intensity in September in West Cornwall?

In September, the average daily maximum UV index in West Cornwall is 4. A UV Index estimate of 3 to 5 represents a medium hazard to health 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
West Cornwall, CT

Average temperature in September - West Cornwall, CT
  • Average high temperature in September: 72°F

The warmest month (with the highest average high temperature) is July (81.1°F).
The month with the lowest average high temperature is January (30.9°F).

  • Average low temperature in September: 53.4°F

The month with the highest average low temperature is July (61.3°F).
The coldest month (with the lowest average low temperature) is January (18.9°F).

Average pressure in September
West Cornwall, CT

Average pressure in September - West Cornwall, 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
West Cornwall, CT

Average wind speed in September - West Cornwall, CT
  • Average wind speed in September: 5.5mph

The windiest months (with the highest average wind speed) are January and March (8mph).
The calmest months (with the lowest average wind speed) are July and August (5mph).

Average humidity in September
West Cornwall, CT

Average humidity in September - West Cornwall, CT
  • Average humidity in September: 80%

The month with the highest relative humidity is February (82%).
The month with the lowest relative humidity is April (74%).

Average rainfall in September
West Cornwall, CT

Average rainfall in September - West Cornwall, CT
  • Average rainfall in September: 2.24"

The wettest month (with the highest rainfall) is July (3.54").
The driest month (with the least rainfall) is January (2.17").

Average rainfall days in September
West Cornwall, CT

Average rainfall days in September - West Cornwall, CT
  • Average rainfall days in September: 13.5 days

The month with the highest number of rainy days is July (17.9 days).
The month with the least rainy days is January (7.7 days).

Average snowfall in September
West Cornwall, CT

Average snowfall in September - West Cornwall, CT
  • Average snowfall in September: 0"

The month with the highest snowfall is February (5.16").
The months with the least snowfall are June, July, August and September (0").

Average snowfall days in September
West Cornwall, CT

Average snowfall days in September - West Cornwall, CT
  • Average snowfall days in September: 0 days

The month with the highest number of snowfall days is February (10.3 days).
The months with the least snowfall days are June, July, August and September (0 days).

Average daylight in September /
Average sunshine in September
West Cornwall, CT

Average daylight in September / Average sunshine in September - West Cornwall, 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 3min

The month with the most sunshine is July (Average sunshine: 10h and 6min).
The month with the least sunshine is February (Average sunshine: 4h and 12min).

Average sunshine days in September
West Cornwall, CT

Average sunshine days in September - West Cornwall, CT
  • Average sunshine days in September: 14.7 days

The month with the most sunshine days is January (16.8 days).
The month with the least sunshine days is June (10.8 days).

Average UV index in September
West Cornwall, CT

Average UV index in September - West Cornwall, CT
  • Average UV index in September: 4

The month with the highest UV index is June (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
West Cornwall, CT

Average cloud cover in September - West Cornwall, CT
  • Average cloud cover in September: 40

The month with the most cloud cover is February (Cloud cover 53).
The months with the least cloud cover are July and August (Cloud cover 37).

Average visibility in September
West Cornwall, CT

Average visibility in September - West Cornwall, CT
  • Average visibility in September: 5mi

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

West Cornwall, Connecticut, USA

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