September weather forecastWilliamsville, VA
September
Weather in September
The first month of the autumn, September, is also a moderately hot month in Williamsville, Virginia, with temperature in the range of an average high of 74.7°F (23.7°C) and an average low of 53.1°F (11.7°C).Temperature
Williamsville's weather in September involves a mild decrease in the average high-temperature, moving down slightly from August's 80.6°F (27°C) to a still warm 74.7°F (23.7°C). September nights experience a distinct temperature drop from the daily highs, with an average low-temperature of 53.1°F (11.7°C).Humidity
The average relative humidity in September is 79%.Rainfall
The month with the least rainfall in Williamsville, Virginia, is September, when the rain falls for 13.3 days and typically collects 1.73" (44mm) of precipitation.Snowfall
In Williamsville, snow does not fall in June through September.Daylight
In Williamsville, Virginia, the average length of the day in September is 12h and 25min.On the first day of September, sunrise is at 6:48 am and sunset at 7:47 pm. On the last day of the month, sunrise is at 7:13 am and sunset at 7:02 pm EDT.
Sunshine
The average sunshine in September is 8.4h.UV index
In Williamsville, the average daily maximum UV index in September is 4. A UV Index value of 3 to 5 symbolizes a moderate health risk from exposure to the Sun's UV radiation for ordinary individuals.Note: A maximum high daily UV index of 4 during September translates into the following directions:
Undertake precautions - It is suggested to shield oneself from sunburn. The intensity of the Sun's UV radiation during midday suggests reducing time spent outdoors. On bright days sunglasses that block both UVA and UVB rays should be worn. A hat with a wide brim is extremely helpful, as it can prevent roughly 50% of UV radiation from reaching the eyes.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Williamsville, VA
- Average high temperature in September: 74.7°F
The warmest month (with the highest average high temperature) is July (82.4°F).
The month with the lowest average high temperature is January (36.7°F).
- Average low temperature in September: 53.1°F
The month with the highest average low temperature is July (59.5°F).
The coldest month (with the lowest average low temperature) is January (22.1°F).
Average pressure in September
Williamsville, VA
- Average pressure in September: 30.06"Hg
The month with the highest atmospheric pressure is November (30.15"Hg).
The month with the lowest atmospheric pressure is June (29.97"Hg).
Average wind speed in September
Williamsville, VA
- Average wind speed in September: 4.2mph
The windiest month (with the highest average wind speed) is February (7.1mph).
The calmest month (with the lowest average wind speed) is August (3.9mph).
Average humidity in September
Williamsville, VA
- Average humidity in September: 79%
The month with the highest relative humidity is December (80%).
The months with the lowest relative humidity are June and July (76%).
Average rainfall in September
Williamsville, VA
- Average rainfall in September: 1.73"
The wettest month (with the highest rainfall) is May (3.23").
The driest month (with the least rainfall) is September (1.73").
Average rainfall days in September
Williamsville, VA
- Average rainfall days in September: 13.3 days
The month with the highest number of rainy days is May (19.7 days).
The month with the least rainy days is November (8.1 days).
Average snowfall in September
Williamsville, VA
- Average snowfall in September: 0"
The month with the highest snowfall is February (9.02").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Williamsville, VA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (10.8 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Williamsville, VA
- Average daylight in September: 12h and 24min
The month with the longest days is June (Average daylight: 14h and 48min).
The month with the shortest days is December (Average daylight: 9h and 36min).
- Average sunshine in September: 8h and 24min
The month with the most sunshine is June (Average sunshine: 10h and 18min).
The month with the least sunshine is January (Average sunshine: 5h and 0min).
Average sunshine days in September
Williamsville, VA
- Average sunshine days in September: 14.3 days
The month with the most sunshine days is November (19.2 days).
The month with the least sunshine days is May (9.2 days).
Average UV index in September
Williamsville, VA
- Average UV index in September: 4
The months with the highest UV index are May, June, July and August (UV index 5).
The months with the lowest UV index are January, February, November and December (UV index 2).
Average cloud cover in September
Williamsville, VA
- Average cloud cover in September: 41
The month with the most cloud cover is February (Cloud cover 50).
The months with the least cloud cover are June, July and November (Cloud cover 36).
Average visibility in September
Williamsville, VA
- Average visibility in September: 4mi
The months with the highest visibility are January, February, March, April, June, July, August, October, November and December (5mi).
The months with the lowest visibility are May and September (4mi).
