Contents
- Weather in September
- Frequently asked questions
- Average temperature in September
- Average pressure in September
- Average wind speed in September
- Average humidity in September
- Average rainfall in September
- Average rainfall days in September
- Average snowfall in September
- Average snowfall days in September
- Average daylight in September
- Average sunshine in September
- Average sunshine days in September
- Average UV index in September
- Average cloud cover in September
- Average visibility in September
Weather in September
Temperature
September ushers in a minor alteration in Cornwall's climate, with the average high-temperature moving from August's moderately hot 79.2°F (26.2°C) to a pleasant 72°F (22.2°C). Cornwall, during the month of September, experiences an average low-temperature of 53.4°F (11.9°C).Humidity
In Cornwall, the average relative humidity in September is 80%.Rainfall
In Cornwall, during September, the rain falls for 13.5 days and regularly aggregates up to 2.24" (57mm) of precipitation. In Cornwall, during the entire year, the rain falls for 160.5 days and collects up to 33.86" (860mm) of precipitation.Snowfall
June through September are months without snowfall.Daylight
In Cornwall, the average length of the day in September is 12h and 28min.On the first day of the month, sunrise is at 6:19 am and sunset at 7:26 pm. On the last day of September, sunrise is at 6:49 am and sunset at 6:36 pm EDT.
Sunshine
In September, the average sunshine is 8.5h.UV index
The average daily maximum UV index in September is 4. A UV Index estimate of 3 to 5 represents a medium health hazard from exposure to the Sun's UV radiation for the ordinary person.Note: The maximum daily UV index of 4 in September interprets into the following recommendations:
Adopt protective measures - Requirement to safeguard skin and eyes from harm exists. The best time to avoid the Sun's harmful UV radiation is during midday when it's most potent. Sunglasses that ward off UVA and UVB rays play a pivotal role in reducing solar eye damage.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the usual temperature for Cornwall in September?
What is the average humidity in September?
How much does it rain in September?
When it does not snow?
Does it snow in September?
What is the average length of the day in September?
When are sunrise and sunset in September?
How many hours of sunshine does Cornwall have in September?
What is the UV index reading in September?
Average temperature in September
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
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
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
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
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
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
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
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
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
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
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
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
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).
Cornwall, Connecticut, USA
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