September weather forecastBrooklyn, CT
September
Weather in September
The first month of the autumn, September, is still a pleasant month in Brooklyn, Connecticut, with an average temperature varying between 55.4°F (13°C) and 72.3°F (22.4°C).Temperature
The move into September indicates a slight reduction in the average high-temperature, down from August's warm 79.7°F (26.5°C) to an agreeable 72.3°F (22.4°C). In Brooklyn, the average nighttime temperature during September is a moderate 55.4°F (13°C).Humidity
February, June, July, September and October, with an average relative humidity of 79%, are the most humid months.Rainfall
September is the month with the least rainfall. Rain falls for 13.6 days and accumulates 1.81" (46mm) of precipitation.Snowfall
In Brooklyn, 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 September in Brooklyn, sunrise is at 6:14 am and sunset at 7:20 pm. On the last day of the month, sunrise is at 6:44 am and sunset at 6:30 pm EDT.
Sunshine
The average sunshine in September in Brooklyn is 8.4h.UV index
The average daily maximum UV index in September in Brooklyn, Connecticut, is 4. A UV Index of 3 to 5 symbolizes a medium health hazard from unsafe exposure to UV radiation for average individuals.Note: The maximum UV index of 4 during September translates into these guidelines:
Make use of precautions - It is urged to ward off sun damage. It's crucial to reduce time in the direct Sun around mid-day due to the intense solar radiation. On bright days sunglasses that block both UVA and UVB rays should be worn. A hat with a wide brim is extremely helpful, as it can prevent roughly 50% of UV radiation from reaching the eyes.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Brooklyn, CT
- Average high temperature in September: 72.3°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 (33.4°F).
- Average low temperature in September: 55.4°F
The month with the highest average low temperature is July (63.1°F).
The coldest month (with the lowest average low temperature) is January (21.6°F).
Average pressure in September
Brooklyn, CT
- Average pressure in September: 30.06"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
Brooklyn, CT
- Average wind speed in September: 6.5mph
The windiest month (with the highest average wind speed) is January (9.3mph).
The calmest month (with the lowest average wind speed) is August (5.9mph).
Average humidity in September
Brooklyn, CT
- Average humidity in September: 79%
The months with the highest relative humidity are February, June, July, September and October (79%).
The month with the lowest relative humidity is April (73%).
Average rainfall in September
Brooklyn, CT
- Average rainfall in September: 1.81"
The wettest month (with the highest rainfall) is December (3.43").
The driest month (with the least rainfall) is September (1.81").
Average rainfall days in September
Brooklyn, CT
- Average rainfall days in September: 13.6 days
The month with the highest number of rainy days is July (17.5 days).
The month with the least rainy days is January (8.3 days).
Average snowfall in September
Brooklyn, CT
- Average snowfall in September: 0"
The month with the highest snowfall is March (3.7").
The months with the least snowfall are June, July, August, September and October (0").
Average snowfall days in September
Brooklyn, CT
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (7.8 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
Brooklyn, CT
- Average daylight in September: 12h and 30min
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 24min
The months with the most sunshine are July and August (Average sunshine: 10h and 12min).
The month with the least sunshine is February (Average sunshine: 4h and 42min).
Average sunshine days in September
Brooklyn, CT
- Average sunshine days in September: 14.6 days
The month with the most sunshine days is November (17.5 days).
The month with the least sunshine days is June (10.6 days).
Average UV index in September
Brooklyn, 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
Brooklyn, CT
- Average cloud cover in September: 38
The months with the most cloud cover are February and March (Cloud cover 49).
The month with the least cloud cover is August (Cloud cover 34).
Average visibility in September
Brooklyn, CT
- Average visibility in September: 5mi
The months with the highest visibility are January, February, March, April, October, November and December (6mi).
The months with the lowest visibility are May, June, July, August and September (5mi).





