September weather forecastMount Vernon, NY
September
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.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
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: 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: 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: 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: 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: 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: 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: 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: 12h and 30min
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 54min
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: 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: 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: 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: 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).
