September weather forecast
Locust Valley, NY

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Weather in September

The first month of the autumn, September, is also a moderately hot month in Locust Valley, New York, with temperature in the range of an average low of 63.5°F (17.5°C) and an average high of 73.4°F (23°C).

Temperature

September brings a slight decrease in the average high-temperature, shifting from a warm 80.4°F (26.9°C) in August to a still moderately hot 73.4°F (23°C). Locust Valley observes an average low-temperature of 63.5°F (17.5°C) during September.

Humidity

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

Rainfall

September is the month with the least rainfall. Rain falls for 12.9 days and accumulates 2.4" (61mm) of precipitation.

Snowfall

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

Daylight

The average length of the day in September is 12h and 27min.
On the first day of September, sunrise is at 6:21 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 September, the average sunshine is 9h.

UV index

In Locust Valley, the average daily maximum UV index in September is 5. A UV Index of 3 to 5 symbolizes a medium vulnerability from unprotected exposure to Sun's UV rays for average individuals.
Note: The maximum daily UV index of 5 in September interprets into the following recommendations:
Preventative actions are necessary - Recommendations to ward off sunburn are given. Solar radiation is at its peak intensity during midday, so it's advisable to stay indoors or in the shade. Safeguard your eyes, ears, and face from sun rays with the aid of a wide-brim hat.
Updated: Feb 13, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What is the average September temperature in Locust Valley?

In September, in Locust Valley, the average high-temperature is 73.4°F (23°C), and the average low-temperature is 63.5°F (17.5°C). The average heat index (a.k.a. 'feels like', 'apparent temperature'), which takes the relative humidity and factors it into the air temperature reading, in July is appraised at 86°F (30°C).

What is the average humidity in September in Locust Valley?

In September, the average relative humidity in Locust Valley, New York, is 73%.

What is the driest month in Locust Valley?

The month with the least rainfall in Locust Valley, 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 Locust Valley in September?

In Locust Valley, in September, during 12.9 rainfall days, 2.4" (61mm) of precipitation is typically accumulated.

When it does not snow in Locust Valley?

May through October are months without snowfall in Locust Valley.

How many hours of daylight does Locust Valley have in September?

In September, the average day length in Locust Valley, New York, is 12h and 27min.

When is the sunrise / sunset in September in Locust Valley?

In September, on the first day of the month, sunrise is at 6:21 am and sunset at 7:26 pm. On the last day of the month, in Locust Valley, sunrise is at 6:50 am and sunset at 6:37 pm EDT.

How many hours of sunshine does Locust Valley have in September?

In Locust Valley, the average sunshine duration in September is 9h.

How high is the UV index in September in Locust Valley?

The average daily maximum UV index in September in Locust Valley is 5. A UV Index value of 3 to 5 symbolizes a moderate health threat 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
Locust Valley, NY

Average temperature in September - Locust Valley, 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).

Average pressure in September
Locust Valley, NY

Average pressure in September - Locust Valley, 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).

Average wind speed in September
Locust Valley, NY

Average wind speed in September - Locust Valley, 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).

Average humidity in September
Locust Valley, NY

Average humidity in September - Locust Valley, 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%).

Average rainfall in September
Locust Valley, NY

Average rainfall in September - Locust Valley, 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").

Average rainfall days in September
Locust Valley, NY

Average rainfall days in September - Locust Valley, 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).

Average snowfall in September
Locust Valley, NY

Average snowfall in September - Locust Valley, 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").

Average snowfall days in September
Locust Valley, NY

Average snowfall days in September - Locust Valley, 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).

Average daylight in September /
Average sunshine in September
Locust Valley, NY

Average daylight in September / Average sunshine in September - Locust Valley, 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).

Average sunshine days in September
Locust Valley, NY

Average sunshine days in September - Locust Valley, 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).

Average UV index in September
Locust Valley, NY

Average UV index in September - Locust Valley, 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).

Average cloud cover in September
Locust Valley, NY

Average cloud cover in September - Locust Valley, 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).

Average visibility in September
Locust Valley, NY

Average visibility in September - Locust Valley, 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).

Locust Valley, New York, USA

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