September weather forecast
Mount Vernon, NY

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Weather in September

September greets Mount Vernon with the mellow rhythms of fall, characterized by a comforting coolness. This month displays a significant drop in temperature, making the city substantially cooler than August. The rainy days turn down a notch, allowing more sunshine to paint the town's canvas. Winds gather momentum, adding a touch of briskness to the settling coolness. The transition from summer to fall is beautifully orchestrated throughout September's weather.

Temperature

The transition into September subtly indicates a reduction in the average high-temperature, down to a still moderately hot 74.7°F (23.7°C) from August's warm 81.9°F (27.7°C). Throughout the nights in September, an average low-temperature of 61.5°F (16.4°C) is noted.

Humidity

The average relative humidity in September is 73%.

Rainfall

In Mount Vernon, in September, during 13.3 rainfall days, 2.32" (59mm) of precipitation is typically accumulated. Throughout the year, there are 156.5 rainfall days, and 33.19" (843mm) of precipitation is accumulated.

Snowfall

May through October are months without snowfall.

Daylight

In September, the average length of the day in Mount Vernon is 12h and 27min.
On the first day of the month, sunrise is at 6:22 am and sunset at 7:27 pm. On the last day of September, sunrise is at 6:51 am and sunset at 6:38 pm EDT.

Sunshine

The average sunshine in September is 8.9h.

UV index

In September, the average daily maximum UV index in Mount Vernon is 5. A UV Index estimate of 3 to 5 represents a medium health hazard from exposure to the Sun's UV rays for ordinary individuals.
Note: The UV index of 5 in September translates into these instructions:
Take care. Persons with lighter skin might suffer burns in less than 30 minutes. Given the potency of the midday Sun's UV radiation, one should avoid prolonged exposure. Outfit yourself in sun-safe attire, like long sleeves, pants, a hat, and UV-blocking sunglasses.

Frequently asked questions

What are September temperatures?

In September, in Mount Vernon, the average high-temperature is 74.7°F (23.7°C), and the average low-temperature is 61.5°F (16.4°C). The average heat index (a.k.a. 'real feel', 'felt air temperature'), which combines relative humidity and air temperature, in August is calculated to be 86°F (30°C).

What is the average humidity in September?

The average relative humidity in September is 73%.

How much does it rain in September?

In Mount Vernon, in September, it is raining for 13.3 days, with typically 2.32" (59mm) of accumulated precipitation.

When it does not snow?

In Mount Vernon, snow does not fall in May through October.

How many hours of daylight does Mount Vernon have in September?

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

What time are sunrise and sunset in September?

On the first day of September, sunrise is at 6:22 am and sunset at 7:27 pm. On the last day of the month, sunrise is at 6:51 am and sunset at 6:38 pm EDT.

How many hours of sunshine does Mount Vernon have in September?

In Mount Vernon, the average sunshine duration in September is 8.9h.

What is the UV index intensity in September?

The average daily maximum UV index in September is 5. A UV Index value of 3 to 5 symbolizes a medium hazard to health from 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
Mount Vernon, NY

Average temperature in September - Mount Vernon, NY
  • Average high temperature in September: 74.7°F

The warmest month (with the highest average high temperature) is July (83.5°F).
The month with the lowest average high temperature is January (36.1°F).

  • Average low temperature in September: 61.5°F

The month with the highest average low temperature is July (69.4°F).
The coldest month (with the lowest average low temperature) is January (25.7°F).

Average pressure in September
Mount Vernon, NY

Average pressure in September - Mount Vernon, 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
Mount Vernon, NY

Average wind speed in September - Mount Vernon, NY
  • Average wind speed in September: 7.1mph

The windiest month (with the highest average wind speed) is January (9.6mph).
The calmest month (with the lowest average wind speed) is July (6.3mph).

Average humidity in September
Mount Vernon, NY

Average humidity in September - Mount Vernon, NY
  • Average humidity in September: 73%

The month with the highest relative humidity is February (76%).
The month with the lowest relative humidity is August (69%).

Average rainfall in September
Mount Vernon, NY

Average rainfall in September - Mount Vernon, NY
  • Average rainfall in September: 2.32"

The wettest month (with the highest rainfall) is July (3.74").
The driest month (with the least rainfall) is February (2.01").

Average rainfall days in September
Mount Vernon, NY

Average rainfall days in September - Mount Vernon, NY
  • Average rainfall days in September: 13.3 days

The month with the highest number of rainy days is July (18.2 days).
The month with the least rainy days is January (8 days).

Average snowfall in September
Mount Vernon, NY

Average snowfall in September - Mount Vernon, NY
  • Average snowfall in September: 0"

The month with the highest snowfall is March (2.6").
The months with the least snowfall are May, June, July, August, September and October (0").

Average snowfall days in September
Mount Vernon, NY

Average snowfall days in September - Mount Vernon, NY
  • Average snowfall days in September: 0 days

The months with the highest number of snowfall days are January and February (5 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).

Average daylight in September /
Average sunshine in September
Mount Vernon, NY

Average daylight in September / Average sunshine in September - Mount Vernon, 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: 8h and 5min

The month with the most sunshine is July (Average sunshine: 10h and 30min).
The month with the least sunshine is February (Average sunshine: 4h and 48min).

Average sunshine days in September
Mount Vernon, NY

Average sunshine days in September - Mount Vernon, NY
  • Average sunshine days in September: 14.6 days

The month with the most sunshine days is November (20.3 days).
The month with the least sunshine days is July (10.7 days).

Average UV index in September
Mount Vernon, NY

Average UV index in September - Mount Vernon, 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
Mount Vernon, NY

Average cloud cover in September - Mount Vernon, NY
  • Average cloud cover in September: 34

The months with the most cloud cover are February, March and December (Cloud cover 47).
The month with the least cloud cover is August (Cloud cover 30).

Average visibility in September
Mount Vernon, NY

Average visibility in September - Mount Vernon, 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).

Mount Vernon, New York, USA

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