September weather forecastCommack, NY
September
Weather in September
September, the first month of the autumn in Commack, is still a pleasant month, with an average temperature fluctuating between 64.8°F (18.2°C) and 72.3°F (22.4°C).Temperature
Commack records a mild change in average high-temperature during September, easing from a moderately hot 78.6°F (25.9°C) in August to a pleasant 72.3°F (22.4°C). Nights in September showcase an average temperature of 64.8°F (18.2°C), slightly cooler than the daytime.Humidity
In September, the average relative humidity is 74%.Rainfall
In September, the rain falls for 13.5 days. Throughout September, 2.64" (67mm) of precipitation is accumulated. In Commack, New York, during the entire year, the rain falls for 155.9 days and collects up to 35.94" (913mm) of precipitation.Snowfall
April through October are months without snowfall.Daylight
In Commack, the average length of the day in September is 12h and 27min.On the first day of September, sunrise is at 6:20 am and sunset at 7:25 pm. On the last day of the month, sunrise is at 6:49 am and sunset at 6:36 pm EDT.
Sunshine
In September, the average sunshine is 9.1h.UV index
The average daily maximum UV index in September is 5. A UV Index of 3 to 5 symbolizes a moderate threat to health from exposure to the Sun's UV rays for the ordinary person.Note: The daily high UV index of 5 during September translates into the following recommendations:
Take precautions - Protection against sunburn is recommended. Midday Sun has the strongest UV rays, making it crucial to limit exposure and find shade. Sunglasses providing both UVA and UVB protection are non-negotiable on sunlit days.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Commack, NY
- Average high temperature in September: 72.3°F
The warmest month (with the highest average high temperature) is July (79.3°F).
The month with the lowest average high temperature is January (37.6°F).
- Average low temperature in September: 64.8°F
The month with the highest average low temperature is August (71.6°F).
The coldest month (with the lowest average low temperature) is January (28.9°F).
Average pressure in September
Commack, NY
- Average pressure in September: 30.05"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
Commack, NY
- Average wind speed in September: 9.6mph
The windiest month (with the highest average wind speed) is January (12.8mph).
The calmest month (with the lowest average wind speed) is July (8.3mph).
Average humidity in September
Commack, NY
- Average humidity in September: 74%
The month with the highest relative humidity is May (77%).
The month with the lowest relative humidity is November (71%).
Average rainfall in September
Commack, NY
- Average rainfall in September: 2.64"
The wettest month (with the highest rainfall) is July (3.94").
The driest month (with the least rainfall) is January (2.2").
Average rainfall days in September
Commack, NY
- Average rainfall days in September: 13.5 days
The month with the highest number of rainy days is July (17.4 days).
The month with the least rainy days is January (7.8 days).
Average snowfall in September
Commack, NY
- Average snowfall in September: 0"
The month with the highest snowfall is March (1.85").
The months with the least snowfall are April, May, June, July, August, September and October (0").
Average snowfall days in September
Commack, NY
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (4.8 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
Commack, NY
- Average daylight in September: 12h and 30min
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: 9h and 6min
The month with the most sunshine is July (Average sunshine: 10h and 48min).
The month with the least sunshine is February (Average sunshine: 4h and 48min).
Average sunshine days in September
Commack, NY
- Average sunshine days in September: 14.7 days
The month with the most sunshine days is November (19.4 days).
The month with the least sunshine days is July (11.4 days).
Average UV index in September
Commack, NY
- Average UV index in September: 5
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
Commack, NY
- Average cloud cover in September: 32
The month with the most cloud cover is December (Cloud cover 48).
The month with the least cloud cover is August (Cloud cover 28).
Average visibility in September
Commack, NY
- 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).





