September weather forecast
Old Westbury, NY

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Weather in September

September, the first month of the autumn in Old Westbury, is also an agreeable month, with an average temperature fluctuating between 64.8°F (18.2°C) and 72.5°F (22.5°C).

Temperature

As September begins, there is a minor decrease in the average high-temperature, softly falling from a warm 79.2°F (26.2°C) in August to an agreeable 72.5°F (22.5°C). Old Westbury's evenings during September maintain an average temperature of 64.8°F (18.2°C), aligning closely with the daytime temperatures.

Humidity

The average relative humidity in September is 73%.

Rainfall

The month with the least rainfall is September, when the rain falls for 8.8 days and typically collects 0.35" (9mm) of precipitation.

Snowfall

In Old Westbury, snow does not fall in April through November.

Daylight

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

Sunshine

In September, the average sunshine is 9h.

UV index

In September, the average daily maximum UV index is 5. A UV Index estimate of 3 to 5 represents a moderate threat to health from exposure to the Sun's UV radiation for the ordinary person.
Note: In September, the maximum UV index of 5 suggests these recommendations:
Exercise prudence. Persons with fair skin could be burned in under 30 minutes. Midday is the peak time for the Sun's radiation; stay in the shade and protect yourself. A wide-brim hat offers excellent sun protection for the eyes, ears, face, and neck. Sunglasses with UVA and UVB protection significantly reduce eye damage from sun exposure.
Updated: Jul 13, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What is the average September temperature?

In September, in Old Westbury, the average high-temperature is 72.5°F (22.5°C), and the average low-temperature is 64.8°F (18.2°C).

What is the average humidity in September?

The average relative humidity in September is 73%.

What is the driest month?

September is the month with the least rainfall. Rain falls for 8.8 days and accumulates 0.35" (9mm) of precipitation.

How many days does it rain in September?

In September, the rain falls for 8.8 days. Throughout September, 0.35" (9mm) of precipitation is accumulated.

When it does not snow?

April through November are months without snowfall.

How many hours of daylight does Old Westbury have in September?

In Old Westbury, the average day length in September is 12h and 27min.

When is the sunrise / sunset in September?

In September, on the first day of the month, 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 long on average sun shines in September?

In Old Westbury, the average sunshine duration in September is 9h.

How high is the UV index in September?

The average daily maximum UV index in September is 5. A UV Index reading of 3 to 5 represents a medium hazard to health from unprotected exposure to UV radiation.
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
Old Westbury, NY

Average temperature in September - Old Westbury, NY
  • Average high temperature in September: 72.5°F

The warmest month (with the highest average high temperature) is July (80.1°F).
The month with the lowest average high temperature is January (37.4°F).

  • Average low temperature in September: 64.8°F

The months with the highest average low temperature are July and August (71.2°F).
The coldest month (with the lowest average low temperature) is January (28.8°F).

Average pressure in September
Old Westbury, NY

Average pressure in September - Old Westbury, 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
Old Westbury, NY

Average wind speed in September - Old Westbury, NY
  • Average wind speed in September: 9.4mph

The windiest month (with the highest average wind speed) is January (12.5mph).
The calmest month (with the lowest average wind speed) is July (8.1mph).

Average humidity in September
Old Westbury, NY

Average humidity in September - Old Westbury, NY
  • Average humidity in September: 73%

The months with the highest relative humidity are May and June (76%).
The month with the lowest relative humidity is November (71%).

Average rainfall in September
Old Westbury, NY

Average rainfall in September - Old Westbury, NY
  • Average rainfall in September: 0.35"

The wettest month (with the highest rainfall) is July (0.87").
The driest month (with the least rainfall) is September (0.35").

Average rainfall days in September
Old Westbury, NY

Average rainfall days in September - Old Westbury, NY
  • Average rainfall days in September: 8.8 days

The month with the highest number of rainy days is July (11.3 days).
The month with the least rainy days is January (5.4 days).

Average snowfall in September
Old Westbury, NY

Average snowfall in September - Old Westbury, NY
  • Average snowfall in September: 0"

The month with the highest snowfall is March (0.43").
The months with the least snowfall are April, May, June, July, August, September, October and November (0").

Average snowfall days in September
Old Westbury, NY

Average snowfall days in September - Old Westbury, NY
  • Average snowfall days in September: 0 days

The month with the highest number of snowfall days is January (4.4 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
Old Westbury, NY

Average daylight in September / Average sunshine in September - Old Westbury, 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 48min).
The month with the least sunshine is February (Average sunshine: 4h and 42min).

Average sunshine days in September
Old Westbury, NY

Average sunshine days in September - Old Westbury, NY
  • Average sunshine days in September: 18.6 days

The month with the most sunshine days is January (22.4 days).
The month with the least sunshine days is July (16.9 days).

Average UV index in September
Old Westbury, NY

Average UV index in September - Old Westbury, 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
Old Westbury, NY

Average cloud cover in September - Old Westbury, NY
  • Average cloud cover in September: 32

The month with the most cloud cover is December (Cloud cover 48).
The months with the least cloud cover are July and August (Cloud cover 28).

Average visibility in September
Old Westbury, NY

Average visibility in September - Old Westbury, 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).

Old Westbury, New York, USA

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