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

A moderate decline in average high-temperatures is noted in September, moving from a moderately hot 81.9°F (27.7°C) in August to a still warm 74.7°F (23.7°C). During the month of September, Mount Vernon anticipates a mean low-temperature of 61.5°F (16.4°C).

Humidity

In September, the average relative humidity is 73%.

Rainfall

In Mount Vernon, during September, the rain falls for 13.3 days and regularly aggregates up to 2.32" (59mm) of precipitation. In Mount Vernon, during the entire year, the rain falls for 156.5 days and collects up to 33.19" (843mm) of precipitation.

Snowfall

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

Daylight

In Mount Vernon, the average length of the day in September is 12h and 27min.
On the first day of September in Mount Vernon, New York, 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.

Sunshine

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

UV index

The average daily maximum UV index in September is 5. A UV Index of 3 to 5 symbolizes a moderate threat to health from unprotected exposure to Sun's UV rays for average individuals.
Note: In September, the UV index of 5 transforms into the following advice:
Adopt protective measures - Requirement to safeguard skin and eyes from harm exists. Direct exposure to the Sun's intense radiation around midday should be avoided for health reasons. Employ a hat with a wide brim for robust protection, cutting UV exposure by half.
Updated: Feb 13, 2024 | Published by: Weather U.S. | About Us / Weather Forecasting / Data Sources

Frequently asked questions

What is the temperature in September in Mount Vernon?

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

What is the average humidity in September in Mount Vernon?

The average relative humidity in September in Mount Vernon is 73%.

How many days does it rain in September in Mount Vernon?

In Mount Vernon, during September, the rain falls for 13.3 days and regularly aggregates up to 2.32" (59mm) of precipitation.

When it does not snow in Mount Vernon?

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

What is the average length of the day in September in Mount Vernon?

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

When are sunrise and sunset in September in Mount Vernon?

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?

The average sunshine duration in September in Mount Vernon is 8.9h.

How high is the UV index in September in Mount Vernon?

In Mount Vernon, 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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