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United StatesThe weather in September in Long Island
It's pleasantly warm in September in Long Island with an average temperature of 22°C. Temperatures this month range from a low of 17°C to a high of 25°C. At night, you can expect temperatures between 9°C and 16°C.
Looking for sun? September isn’t a good month to be in Long Island. The temperature is nice, but there’s too much chance of rain.
Average temperatures and precipitation
This chart shows the average daily maximum and minimum temperatures (in degrees Celsius) and precipitation (in millimeters) in September for Long Island, Maine. A low precipitation value usually indicates little to no rainfall on that day in recent years, while a higher value suggests more frequent rainfall.
Temperature records
With 33°C in 2015, Long Island reached the highest temperature in September over the past 10 years. The lowest daytime temperature in this month was 12°C in 2018. The extreme nighttime temperatures ranged from a lowest recorded value of 1°C to a highest value of 22°C.
Water temperature
The water temperature at Long Island is 18°C this month. You can swim, but it's a bit chilly.
Rainfall amount
In September, there is an average of 110 mm of precipitation, spread over 13 days. The wind speed is around 4 Bft, mostly coming from the South.
Daily weather in September for Long Island
Click on any day in September to get detailed info about the usual weather on that day in Long Island. Check out the historical temperatures and precipitation over the past 10 years on this day.
September weather comparison
| Long Island | New York | |
|---|---|---|
| Average temperature | 22°C | 27°C |
| Max. temperature | 25°C | 31°C |
| Min. temperature | 9°C | -5°C |
| Total precipitation | 110 mm | 57 mm |
| Rainy days | 13 days | 9 days |
Start of September
The month of September starts in Long Island with warm temps, averaging around 24°C during the day and nights around 15°C.
Mid September
By mid-September, daytime temps drop to around 23°C, with nights around 13°C. There’s a chance of some showers during this time, but plenty of dry and sunny days too.
End of September
By the end of September, the average daytime temperature in Long Island is around 22°C, while nighttime temps are about 12°C. A shower might pop up, but overall, the weather will be dry and sunny.
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UV index
The UV index is a maximum of 7 this month. That's a moderate to high value on the intensity scale of 1 to 11. Unprotected skin can burn within 15-25 minutes.
Check out the climate of Long Island for all months and discover the best travel time
Temperature charts
These charts show the average temperatures in September in Long Island, Maine. The temperatures are shown in degrees Celsius and are calculated based on data from the past 10 years.
Daily Temperature in September in Long Island
Temperature in September in Long Island over the years
Precipitation charts
These charts show the average amount of precipitation in September in Long Island, Maine. Precipitation is always measured as water, even when it falls as snow or hail The amount of precipitation is displayed in millimeters, while snowfall is shown in centimeters.
Daily Precipitation in September in Long Island
Total precipitation in September in Long Island over the years
Daily UV index in September in Long Island
This chart shows the average daily UV index in September in Long Island, with the UV index ranging from 0 to a maximum of 11. The bottom of the chart shows the days of the month. Based on historical data, this chart provides an idea of the daily UV radiation levels you can expect.
Weather experiences in September in Long Island
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Average weather in Long Island by month
Click on a month below to see detailed weather info for Long Island. Based on historical weather data, you can see the average temperature, precipitation, wind, and UV index for each day of the month.