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's onset brings a negligible change in high-temperatures, falling from a moderately hot 79.2°F (26.2°C) in August to an agreeable 72.5°F (22.5°C). Old Mystic's temperature drops to an average low of 58.1°F (14.5°C) during the nights of September.Humidity
In Old Mystic, the average relative humidity in September is 78%.Rainfall
September is the month with the least rainfall. Rain falls for 12.1 days and accumulates 1.61" (41mm) of precipitation.Snowfall
June through October are months without snowfall.Daylight
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 September, the average sunshine is 8.5h.UV index
In Old Mystic, 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: In September, the average maximum UV index of 4 translates into the following recommendations:
Exercise prudence. Persons with fair skin could be burned in under 30 minutes. The Sun's UV radiation is especially harmful around midday, so reduce exposure and stay safe. A wide-brim hat offers excellent sun protection for the eyes, ears, face, and neck. Sunglasses with UVA and UVB protection significantly reduce eye damage from sun exposure.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the temperature in September?
What is the average humidity in September?
What is the driest month?
How much does it rain in September?
When it does not snow?
What is the average length of the day in September?
When is the sunrise / sunset in September?
How long on average sun shines in September?
What is the UV index intensity in September?
Average temperature in September
Old Mystic, CT
- Average high temperature in September: 72.5°F
The warmest month (with the highest average high temperature) is July (80.2°F).
The month with the lowest average high temperature is January (35.4°F).
- Average low temperature in September: 58.1°F
The month with the highest average low temperature is July (65.3°F).
The coldest month (with the lowest average low temperature) is January (24.8°F).
Average pressure in September
Old Mystic, 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
Old Mystic, CT
- Average wind speed in September: 7.7mph
The windiest month (with the highest average wind speed) is January (10.6mph).
The calmest month (with the lowest average wind speed) is August (6.8mph).
Average humidity in September
Old Mystic, CT
- Average humidity in September: 78%
The months with the highest relative humidity are June and July (79%).
The month with the lowest relative humidity is April (73%).
Average rainfall in September
Old Mystic, CT
- Average rainfall in September: 1.61"
The wettest month (with the highest rainfall) is December (3.78").
The driest month (with the least rainfall) is September (1.61").
Average rainfall days in September
Old Mystic, CT
- Average rainfall days in September: 12.1 days
The month with the highest number of rainy days is June (16.6 days).
The month with the least rainy days is January (10 days).
Average snowfall in September
Old Mystic, CT
- Average snowfall in September: 0"
The month with the highest snowfall is March (2.56").
The months with the least snowfall are June, July, August, September and October (0").
Average snowfall days in September
Old Mystic, CT
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (7 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
Old Mystic, 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 12min).
- Average sunshine in September: 8h and 3min
The month with the most sunshine is August (Average sunshine: 10h and 24min).
The months with the least sunshine are February and December (Average sunshine: 4h and 48min).
Average sunshine days in September
Old Mystic, CT
- Average sunshine days in September: 15.4 days
The month with the most sunshine days is November (17.7 days).
The month with the least sunshine days is July (11.5 days).
Average UV index in September
Old Mystic, 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
Old Mystic, CT
- Average cloud cover in September: 35
The month with the most cloud cover is March (Cloud cover 49).
The month with the least cloud cover is August (Cloud cover 31).
Average visibility in September
Old Mystic, 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).
Old Mystic, Connecticut, USA
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