September weather forecastWilliamsburg, VA
September
Weather in September
September marks the arrival of fall in Williamsburg, welcoming cooler temperatures ranging from 65.1°F (18.4°C) to 79.9°F (26.6°C). This month witnesses a significant drop in rainfall to only 1.57" (40mm), giving way to drier conditions. The onset of autumn decorates the city with an array of colors, underlined by 12.4 daylight hours that highlight its beauty. Winds pick up slightly, bringing a refreshing change with them. September is a month of transition in Williamsburg, where the beauty of fall begins to unfold against the backdrop of decreasing temperatures.Temperature
With the onset of September, Williamsburg's average high-temperature slightly adjusts, moderately receding from August's tropical 86.5°F (30.3°C) to a warm 79.9°F (26.6°C). In Williamsburg, the average low-temperature during the month of September is a refreshing 65.1°F (18.4°C).Humidity
In September, the average relative humidity is 76%.Rainfall
In Williamsburg, in September, it is raining for 12.7 days, with typically 1.57" (40mm) of accumulated precipitation. In Williamsburg, during the entire year, the rain falls for 148.7 days and collects up to 20.35" (517mm) of precipitation.Snowfall
April through October are months without snowfall.Daylight
The average length of the day in September is 12h and 25min.On the first day of September, sunrise is at 6:37 am and sunset at 7:35 pm. On the last day of the month, sunrise is at 7:02 am and sunset at 6:51 pm EDT.
Sunshine
The average sunshine in September 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 exposure to the Sun's UV radiation for the average person.Note: An average UV index of 5 in September transforms into this advice:
Put precautions into practice - Ensuring skin and eye safety is a necessity. The Sun's UV radiation is especially harmful around midday, so reduce exposure and stay safe. On days when the sun blazes, arm yourself with sunglasses that block UVA and UVB radiation. Attention! Nearly twice the Sun's UV radiation can be reflected by snow.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Williamsburg, VA
- Average high temperature in September: 79.9°F
The warmest month (with the highest average high temperature) is July (88.3°F).
The month with the lowest average high temperature is January (45.1°F).
- Average low temperature in September: 65.1°F
The month with the highest average low temperature is July (71.1°F).
The coldest month (with the lowest average low temperature) is January (31.5°F).
Average pressure in September
Williamsburg, VA
- Average pressure in September: 30.04"Hg
The month with the highest atmospheric pressure is November (30.14"Hg).
The month with the lowest atmospheric pressure is June (29.95"Hg).
Average wind speed in September
Williamsburg, VA
- Average wind speed in September: 6.8mph
The windiest month (with the highest average wind speed) is April (8.6mph).
The calmest month (with the lowest average wind speed) is August (6.1mph).
Average humidity in September
Williamsburg, VA
- Average humidity in September: 76%
The month with the highest relative humidity is December (78%).
The month with the lowest relative humidity is July (73%).
Average rainfall in September
Williamsburg, VA
- Average rainfall in September: 1.57"
The wettest month (with the highest rainfall) is August (2.36").
The driest months (with the least rainfall) are October and December (1.38").
Average rainfall days in September
Williamsburg, VA
- Average rainfall days in September: 12.7 days
The month with the highest number of rainy days is August (16.3 days).
The month with the least rainy days is November (8.5 days).
Average snowfall in September
Williamsburg, VA
- Average snowfall in September: 0"
The month with the highest snowfall is February (0.87").
The months with the least snowfall are April, May, June, July, August, September and October (0").
Average snowfall days in September
Williamsburg, VA
- Average snowfall days in September: 0.1 days
The month with the highest number of snowfall days is January (3.1 days).
The months with the least snowfall days are May, June, July, August and October (0 days).
Average daylight in September /
Average sunshine in September
Williamsburg, 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 36min).
- 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 18min).
Average sunshine days in September
Williamsburg, VA
- Average sunshine days in September: 14.7 days
The months with the most sunshine days are October and November (19.7 days).
The month with the least sunshine days is August (12.2 days).
Average UV index in September
Williamsburg, VA
- Average UV index in September: 5
The month with the highest UV index is June (UV index 7).
The months with the lowest UV index are January and December (UV index 2).
Average cloud cover in September
Williamsburg, 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
Williamsburg, 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).
