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
The onset of September aligns with a soft reduction in the average high-temperature, gently falling from a warm 77.7°F (25.4°C) in August to a pleasant 71.4°F (21.9°C). September witnesses an average nighttime temperature of 59.9°F (15.5°C).Humidity
In September, the average relative humidity is 78%.Rainfall
The month with the least rainfall is September, when the rain falls for 12.8 days and typically collects 1.73" (44mm) of precipitation.Snowfall
May through September are months without snowfall.Daylight
In Stonington, Connecticut, the average length of the day in September is 12h and 28min.On the first day of the month, sunrise is at 6:14 am and sunset at 7:20 pm. On the last day of September, sunrise is at 6:44 am and sunset at 6:30 pm EDT.
Sunshine
In Stonington, the average sunshine in September is 8.9h.UV index
In September, the average daily maximum UV index is 4. A UV Index reading of 3 to 5 represents a moderate health risk from exposure to the Sun's UV radiation for average individuals.Note: A maximum high UV index of 4 in September translates into the following recommendations:
Exercise care. People with light skin might get burns in fewer than 30 minutes. Direct exposure to the Sun's intense radiation around midday should be avoided for health reasons. Tightly woven clothing, when worn loosely, shields effectively against the Sun.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the average September temperature?
What is the average humidity in September in Stonington?
What is the driest month in Stonington?
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?
What time are sunrise and sunset in September?
How long on average sun shines in September?
How high is the UV index in September?
Average temperature in September
Stonington, CT
- Average high temperature in September: 71.4°F
The warmest month (with the highest average high temperature) is July (77.9°F).
The month with the lowest average high temperature is January (36.5°F).
- Average low temperature in September: 59.9°F
The month with the highest average low temperature is July (66.9°F).
The coldest month (with the lowest average low temperature) is January (26.6°F).
Average pressure in September
Stonington, 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
Stonington, CT
- Average wind speed in September: 9.2mph
The windiest month (with the highest average wind speed) is January (12.4mph).
The calmest month (with the lowest average wind speed) is August (8.1mph).
Average humidity in September
Stonington, CT
- Average humidity in September: 78%
The month with the highest relative humidity is June (81%).
The months with the lowest relative humidity are January, March, April and November (74%).
Average rainfall in September
Stonington, CT
- Average rainfall in September: 1.73"
The wettest month (with the highest rainfall) is December (3.86").
The driest month (with the least rainfall) is September (1.73").
Average rainfall days in September
Stonington, CT
- Average rainfall days in September: 12.8 days
The month with the highest number of rainy days is July (17.1 days).
The month with the least rainy days is February (10.1 days).
Average snowfall in September
Stonington, CT
- Average snowfall in September: 0"
The month with the highest snowfall is March (2.44").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in September
Stonington, CT
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (6.8 days).
The months with the least snowfall days are May, June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Stonington, CT
- Average daylight in September: 12h and 3min
The month with the longest days is June (Average daylight: 15h and 6min).
The month with the shortest days is December (Average daylight: 9h and 18min).
- Average sunshine in September: 8h and 5min
The month with the most sunshine is August (Average sunshine: 10h and 36min).
The months with the least sunshine are February and December (Average sunshine: 4h and 54min).
Average sunshine days in September
Stonington, CT
- Average sunshine days in September: 15.2 days
The month with the most sunshine days is November (16.5 days).
The months with the least sunshine days are June and July (11.7 days).
Average UV index in September
Stonington, 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 and December (UV index 2).
Average cloud cover in September
Stonington, CT
- Average cloud cover in September: 32
The months with the most cloud cover are February, March and December (Cloud cover 47).
The month with the least cloud cover is August (Cloud cover 28).
Average visibility in September
Stonington, CT
- Average visibility in September: 6mi
The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
Stonington, Connecticut, USA
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