September weather forecastBristow, VA
September
Weather in September
September, the first month of the autumn in Bristow, is also a moderately hot month, with an average temperature varying between 79°F (26.1°C) and 59.7°F (15.4°C).Temperature
The start of September involves a subtle temperature drop, shifting from a moderately hot 85.8°F (29.9°C) in August to a still warm 79°F (26.1°C). In the month of September, Bristow experiences an average low-temperature of 59.7°F (15.4°C).Humidity
In September, the average relative humidity is 76%.Rainfall
The month with the least rainfall is September, when the rain falls for 12.7 days and typically collects 1.93" (49mm) of precipitation.Snowfall
In Bristow, snow does not fall in May through October.Daylight
In Bristow, the average length of the day in September is 12h and 26min.On the first day of September, sunrise is at 6:39 am and sunset at 7:39 pm. On the last day of the month, sunrise is at 7:05 am and sunset at 6:54 pm EDT.
Sunshine
The average sunshine in September is 8.7h.UV index
The average daily maximum UV index in September in Bristow is 5. A UV Index value of 3 to 5 symbolizes a medium vulnerability from exposure to the Sun's UV radiation for average individuals.Note: The daily maximum UV index of 5 in September interprets into the following advice:
Take necessary precautions - Defending against sun damage is advocated. The best time to avoid the Sun's harmful UV radiation is during midday when it's most potent. Sun-related eye harm can be minimized with proper sunglasses offering UVA and UVB coverage.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Bristow, VA
- Average high temperature in September: 79°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 (40.6°F).
- Average low temperature in September: 59.7°F
The month with the highest average low temperature is July (67.1°F).
The coldest month (with the lowest average low temperature) is January (26.4°F).
Average pressure in September
Bristow, VA
- Average pressure in September: 30.05"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
Bristow, VA
- Average wind speed in September: 5.1mph
The windiest months (with the highest average wind speed) are March and April (7mph).
The calmest month (with the lowest average wind speed) is August (4.6mph).
Average humidity in September
Bristow, 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 (72%).
Average rainfall in September
Bristow, VA
- Average rainfall in September: 1.93"
The wettest month (with the highest rainfall) is August (3.43").
The driest month (with the least rainfall) is September (1.93").
Average rainfall days in September
Bristow, VA
- Average rainfall days in September: 12.7 days
The month with the highest number of rainy days is May (17.4 days).
The month with the least rainy days is November (9.3 days).
Average snowfall in September
Bristow, VA
- Average snowfall in September: 0"
The month with the highest snowfall is January (3.7").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in September
Bristow, VA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (5.2 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
Bristow, 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 30min).
- Average sunshine in September: 8h and 42min
The month with the most sunshine is July (Average sunshine: 10h and 42min).
The months with the least sunshine are January, February and December (Average sunshine: 5h and 12min).
Average sunshine days in September
Bristow, VA
- Average sunshine days in September: 15.9 days
The month with the most sunshine days is November (19.8 days).
The month with the least sunshine days is May (11.7 days).
Average UV index in September
Bristow, VA
- Average UV index in September: 5
The months with the highest UV index are May, June, July and August (UV index 6).
The months with the lowest UV index are January, February, November and December (UV index 2).
Average cloud cover in September
Bristow, VA
- Average cloud cover in September: 38
The month with the most cloud cover is March (Cloud cover 47).
The month with the least cloud cover is July (Cloud cover 31).
Average visibility in September
Bristow, VA
- Average visibility in September: 5mi
The months with the highest visibility are January, February, March, April, June, July, August and November (6mi).
The months with the lowest visibility are May, September, October and December (5mi).
