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 indicates a minor shift in the average high-temperature, from August's moderately hot 78.4°F (25.8°C) to an agreeable 72.1°F (22.3°C). A minor drop in temperature is observed from daytime highs in Islip Terrace, New York, during the nights of September, averaging a comfortable 65.3°F (18.5°C).Humidity
In September, the average relative humidity is 74%.Rainfall
In Islip Terrace, in September, during 13.5 rainfall days, 2.56" (65mm) of precipitation is typically accumulated. Throughout the year, there are 153.2 rainfall days, and 34.45" (875mm) of precipitation is accumulated.Snowfall
In Islip Terrace, snow does not fall in April through September.Daylight
In Islip Terrace, the average length of the day in September is 12h and 27min.On the first day of September in Islip Terrace, sunrise is at 6:20 am and sunset at 7:24 pm. On the last day of the month, sunrise is at 6:48 am and sunset at 6:36 pm EDT.
Sunshine
In Islip Terrace, the average sunshine in September is 9.1h.UV index
In Islip Terrace, the average daily maximum UV index in September is 5. A UV Index of 3 to 5 symbolizes a medium health hazard from unprotected exposure to Sun's UV rays for average individuals.Note: A typical high UV index of 5 in September suggests the following recommendations:
Guard yourself - Precautionary measures against sun damage are advocated. Avoid the Sun's strongest UV rays by seeking shade and limiting exposure during midday. Stay sun-safe with clothing that is both closely woven and worn loosely.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the usual temperature for Islip Terrace in September?
What is the average humidity in September in Islip Terrace?
How many days does it rain in September in Islip Terrace?
When it does not snow in Islip Terrace?
Does it snow in Islip Terrace in September?
What is the average length of the day in September in Islip Terrace?
When is the sunrise / sunset in September in Islip Terrace?
How many hours of sunshine does Islip Terrace have in September?
How high is the UV index in September in Islip Terrace?
Average temperature in September
Islip Terrace, NY
- Average high temperature in September: 72.1°F
The warmest month (with the highest average high temperature) is July (79°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 (72°F).
The coldest month (with the lowest average low temperature) is January (30°F).
Average pressure in September
Islip Terrace, 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
Islip Terrace, NY
- Average wind speed in September: 10.1mph
The windiest month (with the highest average wind speed) is January (13.4mph).
The calmest month (with the lowest average wind speed) is July (8.6mph).
Average humidity in September
Islip Terrace, NY
- Average humidity in September: 74%
The months with the highest relative humidity are May and June (77%).
The month with the lowest relative humidity is November (71%).
Average rainfall in September
Islip Terrace, NY
- Average rainfall in September: 2.56"
The wettest month (with the highest rainfall) is July (3.86").
The driest month (with the least rainfall) is January (2.05").
Average rainfall days in September
Islip Terrace, NY
- Average rainfall days in September: 13.5 days
The month with the highest number of rainy days is July (17.9 days).
The month with the least rainy days is January (7.6 days).
Average snowfall in September
Islip Terrace, NY
- Average snowfall in September: 0"
The month with the highest snowfall is March (1.97").
The months with the least snowfall are April, May, June, July, August and September (0").
Average snowfall days in September
Islip Terrace, NY
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (4.2 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
Islip Terrace, NY
- Average daylight in September: 12h and 3min
The month with the longest days is June (Average daylight: 15h and 0min).
The month with the shortest days is December (Average daylight: 9h and 18min).
- Average sunshine in September: 9h and 1min
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
Islip Terrace, NY
- Average sunshine days in September: 14.7 days
The month with the most sunshine days is November (19.7 days).
The month with the least sunshine days is July (11.2 days).
Average UV index in September
Islip Terrace, 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
Islip Terrace, 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
Islip Terrace, 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).
Islip Terrace, New York, USA
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