September weather forecastSterling, VA
September
Weather in September
September in Sterling, Virginia, signifies the smooth transition from the hot summer to the pleasant fall season. The temperatures see a notable dip from August, offering a suitable climate for various outdoor activities. The reduced heat and rainfall allow for the onset of fall and its associated color transformation of the cityscape. Social gatherings and events gain momentum, attributing to the pleasant weather, minimizing the heat extremes of the previous months. It represents a breath of fresh air, as the cityscape begins to transform, heralding the arrival of the fall colors.Temperature
As August shifts into September, a minor alteration in temperatures is observed, with average highs reducing from a warm 85.6°F (29.8°C) to a still moderately hot 78.3°F (25.7°C). In the month of September, Sterling witnesses a consistent average low-temperature of 59.7°F (15.4°C).Humidity
The average relative humidity in September is 75%.Rainfall
September is the month with the least rainfall. Rain falls for 12.6 days and accumulates 1.93" (49mm) of precipitation.Snowfall
May through October are months without snowfall.Daylight
In September, the average length of the day 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 6:53 pm EDT.
Sunshine
In September, the average sunshine is 8.7h.UV index
In Sterling, the average daily maximum UV index in September is 5. A UV Index of 3 to 5 symbolizes a medium vulnerability from unprotected exposure to Sun's UV rays for average individuals.Note: The maximum UV index of 5 during September translates into these guidelines:
Ensure safety - Sun damage prevention is strongly urged. Considering the Sun's intensity during midday, it's wise to minimize direct exposure. Sun-protective clothing, a long-sleeved shirt and pants, a wide-brimmed hat, and UVA and UVB-blocking sunglasses are particularly helpful in blocking UV radiation's harmful effects.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Sterling, VA
- Average high temperature in September: 78.3°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 (39.7°F).
- Average low temperature in September: 59.7°F
The month with the highest average low temperature is July (67.3°F).
The coldest month (with the lowest average low temperature) is January (25.9°F).
Average pressure in September
Sterling, 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
Sterling, VA
- Average wind speed in September: 5.3mph
The windiest month (with the highest average wind speed) is March (7.5mph).
The calmest month (with the lowest average wind speed) is August (4.7mph).
Average humidity in September
Sterling, 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 (70%).
Average rainfall in September
Sterling, VA
- Average rainfall in September: 1.93"
The wettest month (with the highest rainfall) is August (3.78").
The driest month (with the least rainfall) is September (1.93").
Average rainfall days in September
Sterling, VA
- Average rainfall days in September: 12.6 days
The month with the highest number of rainy days is May (17.5 days).
The month with the least rainy days is January (9.3 days).
Average snowfall in September
Sterling, VA
- Average snowfall in September: 0"
The month with the highest snowfall is January (3.54").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in September
Sterling, VA
- Average snowfall days in September: 0 days
The months with the highest number of snowfall days are January and February (5.1 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
Sterling, VA
- Average daylight in September: 12h and 24min
The month with the longest days is June (Average daylight: 14h and 54min).
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 0min).
Average sunshine days in September
Sterling, VA
- Average sunshine days in September: 15.9 days
The month with the most sunshine days is November (19.5 days).
The month with the least sunshine days is July (11.8 days).
Average UV index in September
Sterling, 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
Sterling, VA
- Average cloud cover in September: 38
The month with the most cloud cover is March (Cloud cover 48).
The month with the least cloud cover is July (Cloud cover 31).
Average visibility in September
Sterling, VA
- Average visibility in September: 6mi
The months with the highest visibility are January, February, March, April, June, July, August, September, October, November and December (6mi).
The month with the lowest visibility is May (5mi).
