September weather forecast
Bristow, VA

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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.
Updated: Feb 14, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What are the temperatures in Bristow in September?

The high-temperature in Bristow, Virginia, during September is 79°F (26.1°C) and the low-temperature is 59.7°F (15.4°C). The average heat index (a.k.a. 'felt air temperature', 'feels like'), which combines relative humidity and air temperature, in August is computed to be 96.8°F (36°C).

What is the average humidity in September in Bristow?

In Bristow, Virginia, the average relative humidity in September is 76%.

What is the driest month in Bristow?

The month with the least rainfall in Bristow is September, when the rain falls for 12.7 days and typically collects 1.93" (49mm) of precipitation.

How many days does it rain in September in Bristow?

In Bristow, in September, it is raining for 12.7 days, with typically 1.93" (49mm) of accumulated precipitation.

When it does not snow in Bristow?

May through October are months without snowfall.

What is the average length of the day in September in Bristow?

The average day length in September in Bristow is 12h and 26min.

When is the sunrise / sunset in September in Bristow?

In September, on the first day of the month, sunrise is at 6:39 am and sunset at 7:39 pm. On the last day of the month, in Bristow, sunrise is at 7:05 am and sunset at 6:54 pm EDT.

How many hours of sunshine does Bristow have in September?

In Bristow, Virginia, the average sunshine duration in September is 8.7h.

What is the UV index intensity in September in Bristow?

The average daily maximum UV index in September in Bristow is 5. A UV Index value of 3 to 5 symbolizes a medium health risk from exposure to Sun's UV rays.
Average humidity
Average rainfall days
Average snowfall
Average snowfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in September
Bristow, VA

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 - 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 - 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 - 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 - 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 - 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 - 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 - 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 / Average sunshine in September - Bristow, VA
  • Average daylight in September: 12h and 2min

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 4min

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 - 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 - 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 - 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 - 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).

Bristow, Virginia, USA

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