September weather forecast
Roslyn, NY

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Weather in September

September, the first month of the autumn in Roslyn, is also a moderately hot month, with an average temperature ranging between max 73.4°F (23°C) and min 63.5°F (17.5°C).

Temperature

During the shift to September, a minor reduction in average high-temperature is observed, shifting from a moderately hot 80.4°F (26.9°C) in August to a still warm 73.4°F (23°C). The low-temperature averages to an enjoyable 63.5°F (17.5°C) during the nights of September.

Humidity

In Roslyn, the average relative humidity in September is 73%.

Rainfall

The month with the least rainfall is September, when the rain falls for 12.9 days and typically collects 2.4" (61mm) of precipitation.

Snowfall

In Roslyn, New York, snow does not fall in May through October.

Ocean temperature

In Roslyn, the average seawater temperature in September is 70.2°F (21.2°C).
Note: Most individuals do not find swimming at 70.2°F (21.2°C) to be enjoyable. As the water temperature declines below 69.8°F (21°C), maintaining control over one's breathing becomes harder.

Daylight

The average length of the day in September in Roslyn, New York, is 12h and 27min.
On the first day of September in Roslyn, sunrise is at 6:22 am and sunset at 7:26 pm. On the last day of the month, sunrise is at 6:50 am and sunset at 6:37 pm EDT.

Sunshine

In Roslyn, the average sunshine in September is 9h.

UV index

The average daily maximum UV index in September is 5. A UV Index estimate of 3 to 5 represents a moderate health risk from exposure to the Sun's UV rays for the average person.
Note: The maximum daily UV index of 5 in September converts into the following recommendations:
Safety measures are advised. Light-skinned individuals may experience burns in under half an hour. Solar radiation is at its peak intensity during midday, so it's advisable to stay indoors or in the shade. Sunglasses providing both UVA and UVB protection are non-negotiable on sunlit days. Stay aware! UV radiation is magnified when reflecting off sand and water.
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Frequently asked questions

What is the usual temperature for Roslyn in September?

Roslyn in September has an average high-temperature of 73.4°F (23°C) and an average low-temperature of 63.5°F (17.5°C). The average heat index (a.k.a. 'feels like', 'real feel'), which combines air temperature and relative humidity, in July is computed to be 86°F (30°C).

What is the average humidity in September in Roslyn?

The average relative humidity in September in Roslyn is 73%.

What is the driest month in Roslyn?

The month with the least rainfall in Roslyn, New York, is September, when the rain falls for 12.9 days and typically collects 2.4" (61mm) of precipitation.

How much does it rain in Roslyn in September?

In September, in Roslyn, the rain falls for 12.9 days. Throughout September, 2.4" (61mm) of precipitation is accumulated.

When it does not snow in Roslyn?

In Roslyn, New York, snow does not fall in May through October.

How cold is the water in September in Roslyn?

In September, the average ocean temperature in Roslyn, New York, is 70.2°F (21.2°C). Swimming in 70.2°F (21.2°C) is not enjoyable for the majority. Controlling breathing becomes progressively more difficult as surface water temperature decreases below 69.8°F (21°C).

How many hours of daylight does Roslyn have in September?

The average day length in September is 12h and 27min.

What time are sunrise and sunset in September in Roslyn?

On the first day of September, sunrise is at 6:22 am and sunset at 7:26 pm. On the last day of the month, sunrise is at 6:50 am and sunset at 6:37 pm EDT.

How many hours of sunshine does Roslyn have in September?

The average sunshine duration in September in Roslyn, New York, is 9h.

What is the UV index reading in September in Roslyn?

In September, the average daily maximum UV index in Roslyn is 5. A UV Index estimate of 3 to 5 represents a medium hazard to health from unsafe exposure to Sun's UV rays.
Average humidity
Average rainfall days
Average snowfall
Average snowfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in September
Roslyn, NY

Average temperature in September - Roslyn, NY
  • Average high temperature in September: 73.4°F

The warmest month (with the highest average high temperature) is July (81.5°F).
The month with the lowest average high temperature is January (36.5°F).

  • Average low temperature in September: 63.5°F

The months with the highest average low temperature are July and August (70.3°F).
The coldest month (with the lowest average low temperature) is January (27.3°F).

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Average pressure in September
Roslyn, NY

Average pressure in September - Roslyn, NY
  • Average pressure in September: 30.05"Hg

The month with the highest atmospheric pressure is November (30.1"Hg).
The month with the lowest atmospheric pressure is June (29.93"Hg).

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Average wind speed in September
Roslyn, NY

Average wind speed in September - Roslyn, NY
  • Average wind speed in September: 8.3mph

The windiest month (with the highest average wind speed) is January (11.2mph).
The calmest month (with the lowest average wind speed) is July (7.3mph).

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Average humidity in September
Roslyn, NY

Average humidity in September - Roslyn, NY
  • Average humidity in September: 73%

The months with the highest relative humidity are February, May and December (75%).
The months with the lowest relative humidity are August and November (71%).

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Average rainfall in September
Roslyn, NY

Average rainfall in September - Roslyn, NY
  • Average rainfall in September: 2.4"

The wettest month (with the highest rainfall) is December (4.06").
The driest month (with the least rainfall) is September (2.4").

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Average rainfall days in September
Roslyn, NY

Average rainfall days in September - Roslyn, NY
  • Average rainfall days in September: 12.9 days

The month with the highest number of rainy days is July (17.9 days).
The month with the least rainy days is January (9.3 days).

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Average snowfall in September
Roslyn, NY

Average snowfall in September - Roslyn, NY
  • Average snowfall in September: 0"

The month with the highest snowfall is March (2.01").
The months with the least snowfall are May, June, July, August, September and October (0").

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Average snowfall days in September
Roslyn, NY

Average snowfall days in September - Roslyn, NY
  • Average snowfall days in September: 0 days

The month with the highest number of snowfall days is January (6.8 days).
The months with the least snowfall days are June, July, August, September and October (0 days).

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Average sea temperature in September
Roslyn, NY

Average sea temperature in September - Roslyn, NY
  • Average sea temperature in September: 70.1°F

The best month for swimming (with the highest average sea temperature) is August (74.1°F).
The coldest month (with the lowest average sea temperature) is February (39.9°F).

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Average daylight in September /
Average sunshine in September
Roslyn, NY

Average daylight in September / Average sunshine in September - Roslyn, NY
  • Average daylight in September: 12h and 3min

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 0min

The month with the most sunshine is July (Average sunshine: 10h and 42min).
The month with the least sunshine is February (Average sunshine: 4h and 48min).

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Average sunshine days in September
Roslyn, NY

Average sunshine days in September - Roslyn, NY
  • Average sunshine days in September: 15.2 days

The month with the most sunshine days is November (18 days).
The month with the least sunshine days is July (10.6 days).

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Average UV index in September
Roslyn, NY

Average UV index in September - Roslyn, 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, November and December (UV index 2).

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Average cloud cover in September
Roslyn, NY

Average cloud cover in September - Roslyn, NY
  • Average cloud cover in September: 33

The months with the most cloud cover are February and December (Cloud cover 47).
The months with the least cloud cover are July and August (Cloud cover 29).

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Average visibility in September
Roslyn, NY

Average visibility in September - Roslyn, 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).

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Roslyn, New York, USA

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