September weather forecastIslandia, NY
September
Weather in September
The first month of the autumn, September, is also an agreeable month in Islandia, New York, with an average temperature varying between 65.3°F (18.5°C) and 72.1°F (22.3°C).Temperature
September reveals a small adjustment in temperature, transitioning from an average high of a moderately hot 78.1°F (25.6°C) in August to a pleasant 72.1°F (22.3°C). Islandia's September nights experience a subtle temperature dip to an average of 65.3°F (18.5°C).Humidity
In Islandia, New York, the average relative humidity in September is 74%.Rainfall
In September, the rain falls for 12.8 days. Throughout September, 2.48" (63mm) of precipitation is accumulated. In Islandia, New York, during the entire year, the rain falls for 155.3 days and collects up to 34.84" (885mm) of precipitation.Snowfall
April, June through September and November are months without snowfall.Daylight
In September, the average length of the day in Islandia is 12h and 27min.On the first day of the month, sunrise is at 6:20 am and sunset at 7:24 pm. On the last day of September, sunrise is at 6:48 am and sunset at 6:35 pm EDT.
Sunshine
In September, the average sunshine in Islandia is 9.2h.UV index
The average daily maximum UV index in September is 5. A UV Index value of 3 to 5 symbolizes a moderate health risk from exposure to the Sun's UV radiation for average individuals.Note: The maximum daily UV index, 5 in September, converts into the following recommendations:
Make use of precautions - Suggestions to resist sunburn are communicated. Direct Sun exposure should be minimized especially during midday when radiation is most intense. Sunglasses that guard against UVA and UVB rays are pivotal in minimizing sun-induced ocular damage.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Islandia, NY
- Average high temperature in September: 72.1°F
The warmest month (with the highest average high temperature) is August (78.1°F).
The month with the lowest average high temperature is January (37.9°F).
- Average low temperature in September: 65.3°F
The month with the highest average low temperature is August (71.8°F).
The coldest month (with the lowest average low temperature) is January (30.2°F).
Average pressure in September
Islandia, 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
Islandia, NY
- Average wind speed in September: 10.4mph
The windiest month (with the highest average wind speed) is January (13.8mph).
The calmest months (with the lowest average wind speed) are July and August (9mph).
Average humidity in September
Islandia, NY
- Average humidity in September: 74%
The months with the highest relative humidity are May and June (78%).
The month with the lowest relative humidity is November (71%).
Average rainfall in September
Islandia, NY
- Average rainfall in September: 2.48"
The wettest month (with the highest rainfall) is December (3.74").
The driest month (with the least rainfall) is January (2.17").
Average rainfall days in September
Islandia, NY
- Average rainfall days in September: 12.8 days
The month with the highest number of rainy days is July (17.7 days).
The month with the least rainy days is January (8.3 days).
Average snowfall in September
Islandia, NY
- Average snowfall in September: 0"
The month with the highest snowfall is March (2.13").
The months with the least snowfall are April, June, July, August, September and November (0").
Average snowfall days in September
Islandia, NY
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (4.6 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Islandia, 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 12min
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
Islandia, NY
- Average sunshine days in September: 15.1 days
The month with the most sunshine days is November (18.8 days).
The month with the least sunshine days is July (11.3 days).
Average UV index in September
Islandia, 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
Islandia, NY
- Average cloud cover in September: 31
The month with the most cloud cover is December (Cloud cover 48).
The month with the least cloud cover is August (Cloud cover 27).
Average visibility in September
Islandia, 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).





