September weather forecastYorktown, VA
September
Weather in September
The clicking of the calendar to September in Yorktown brings about a transition from the hot summer to the crisp fall. The cooler temperatures, reduced sunlight hours and the minimal sea temperature give the first hints of autumn. The city experiences the least amount of rainfall, creating a predominately dry environment. The wind speeds remain fairly stagnant, and cloud cover decreases slightly, allowing for great visibility. Yorktown thrives in September's splendid fall weather, presenting a dramatic display of autumn hues and comfortable climate.Temperature
September's onset introduces a mild reduction in the average high-temperature, from 85.6°F (29.8°C) in August to a still warm 79.9°F (26.6°C). Yorktown observes an average nighttime low-temperature of 66.6°F (19.2°C) during the month of September.Humidity
In Yorktown, the average relative humidity in September is 75%.Rainfall
September is the month with the least rainfall in Yorktown. Rain falls for 13 days and accumulates 2.4" (61mm) of precipitation.Snowfall
April through October are months without snowfall.Ocean temperature
In Yorktown, in September, the average water temperature is 76.3°F (24.6°C).Note: For those with a heightened sensitivity to cold, sunshine, wind, and outside temperature make a big difference in enjoying a swim at 76.3°F (24.6°C). (Olympic swimming regulations state a water temperature of 77°F (25°C) to 82.4°F (28°C).)
Daylight
In September, the average length of the day is 12h and 25min.On the first day of the month, sunrise is at 6:37 am and sunset at 7:34 pm. On the last day of September, sunrise is at 7:01 am and sunset at 6:50 pm EDT.
Sunshine
In September, the average sunshine is 9.2h.UV index
In September, the average daily maximum UV index is 5. A UV Index value of 3 to 5 symbolizes a medium health hazard from unprotected exposure to Sun's UV rays for the ordinary person.Note: A maximum UV index of 5 in September translates into the following recommendations:
Take necessary precautions - Defending against sun damage is advocated. The mid-day Sun emits the most powerful UV radiation, so seek shade and minimize exposure. Sunglasses that ward off UVA and UVB rays play a pivotal role in reducing solar eye damage. Attention! The reflection of both water and sand can increase the intensity of UV rays.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Yorktown, VA
- Average high temperature in September: 79.9°F
The warmest month (with the highest average high temperature) is July (87.8°F).
The month with the lowest average high temperature is January (45.1°F).
- Average low temperature in September: 66.6°F
The month with the highest average low temperature is July (72.3°F).
The coldest month (with the lowest average low temperature) is January (32.5°F).
Average pressure in September
Yorktown, VA
- Average pressure in September: 30.03"Hg
The month with the highest atmospheric pressure is November (30.13"Hg).
The month with the lowest atmospheric pressure is June (29.95"Hg).
Average wind speed in September
Yorktown, VA
- Average wind speed in September: 7.6mph
The windiest month (with the highest average wind speed) is April (9.5mph).
The calmest month (with the lowest average wind speed) is August (6.8mph).
Average humidity in September
Yorktown, VA
- Average humidity in September: 75%
The month with the highest relative humidity is December (78%).
The month with the lowest relative humidity is July (72%).
Average rainfall in September
Yorktown, VA
- Average rainfall in September: 2.4"
The wettest month (with the highest rainfall) is August (3.62").
The driest month (with the least rainfall) is September (2.4").
Average rainfall days in September
Yorktown, VA
- Average rainfall days in September: 13 days
The month with the highest number of rainy days is May (17.6 days).
The month with the least rainy days is November (9.6 days).
Average snowfall in September
Yorktown, VA
- Average snowfall in September: 0"
The month with the highest snowfall is February (1.34").
The months with the least snowfall are April, May, June, July, August, September and October (0").
Average snowfall days in September
Yorktown, VA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (3 days).
The months with the least snowfall days are April, May, June, July, August, September and October (0 days).
Average sea temperature in September
Yorktown, VA
- Average sea temperature in September: 76.2°F
The best month for swimming (with the highest average sea temperature) is August (79.6°F).
The coldest month (with the lowest average sea temperature) is February (48.7°F).
Average daylight in September /
Average sunshine in September
Yorktown, VA
- Average daylight in September: 12h and 24min
The month with the longest days is June (Average daylight: 14h and 42min).
The month with the shortest days is December (Average daylight: 9h and 42min).
- Average sunshine in September: 9h and 12min
The month with the most sunshine is July (Average sunshine: 10h and 48min).
The month with the least sunshine is February (Average sunshine: 5h and 12min).
Average sunshine days in September
Yorktown, VA
- Average sunshine days in September: 15.2 days
The month with the most sunshine days is November (18.6 days).
The month with the least sunshine days is May (11.5 days).
Average UV index in September
Yorktown, VA
- Average UV index in September: 5
The months with the highest UV index are June and July (UV index 7).
The months with the lowest UV index are January and December (UV index 2).
Average cloud cover in September
Yorktown, VA
- Average cloud cover in September: 34
The month with the most cloud cover is March (Cloud cover 45).
The month with the least cloud cover is July (Cloud cover 28).
Average visibility in September
Yorktown, VA
- 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).
