September weather forecastDale City, VA
September
Weather in September
September, the first month of the autumn in Dale City, is still a warm month, with an average temperature varying between 61°F (16.1°C) and 79.2°F (26.2°C).Temperature
September's arrival signals a moderate reduction in the average high-temperature, easing from a hot 86°F (30°C) in August to a moderately hot 79.2°F (26.2°C). In September, Dale City records an average nighttime temperature of 61°F (16.1°C).Humidity
In September, the average relative humidity in Dale City is 76%.Rainfall
In Dale City, in September, it is raining for 8.8 days, with typically 0.51" (13mm) of accumulated precipitation. Throughout the year, there are 105.2 rainfall days, and 9.21" (234mm) of precipitation is accumulated.Snowfall
May through October are months without snowfall.Daylight
In Dale City, the average length of the day in September is 12h and 26min.On the first day of the month, sunrise is at 6:39 am and sunset at 7:38 pm. On the last day of September, sunrise is at 7:04 am and sunset at 6:53 pm EDT.
Sunshine
The average sunshine in September is 8.9h.UV index
In September, the average daily maximum UV index is 5. A UV Index value of 3 to 5 symbolizes a moderate health risk from exposure to the Sun's UV rays for the ordinary person.Note: A daily high UV index of 5 in September leads to these guidelines:
Exercise prevention - Protecting skin and eyes from harm is required. Protect yourself from the midday Sun's peak UV radiation by minimizing exposure. Fend off the sun's harsh rays with appropriate clothing, a wide-brim hat, and UV-protective sunglasses.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Dale City, VA
- Average high temperature in September: 79.2°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 (41°F).
- Average low temperature in September: 61°F
The month with the highest average low temperature is July (68.2°F).
The coldest month (with the lowest average low temperature) is January (27°F).
Average pressure in September
Dale City, 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
Dale City, VA
- Average wind speed in September: 5.3mph
The windiest months (with the highest average wind speed) are March and April (7.1mph).
The calmest month (with the lowest average wind speed) is August (4.7mph).
Average humidity in September
Dale City, VA
- Average humidity in September: 76%
The months with the highest relative humidity are October and December (77%).
The month with the lowest relative humidity is July (72%).
Average rainfall in September
Dale City, VA
- Average rainfall in September: 0.51"
The wettest month (with the highest rainfall) is August (1.18").
The driest month (with the least rainfall) is January (0.47").
Average rainfall days in September
Dale City, VA
- Average rainfall days in September: 8.8 days
The month with the highest number of rainy days is May (11.7 days).
The month with the least rainy days is November (5.5 days).
Average snowfall in September
Dale City, VA
- Average snowfall in September: 0"
The month with the highest snowfall is January (0.83").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in September
Dale City, VA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (3.3 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
Dale City, 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 54min
The month with the most sunshine is July (Average sunshine: 10h and 48min).
The months with the least sunshine are February and December (Average sunshine: 5h and 12min).
Average sunshine days in September
Dale City, VA
- Average sunshine days in September: 18.2 days
The month with the most sunshine days is November (23.1 days).
The month with the least sunshine days is May (16.9 days).
Average UV index in September
Dale City, 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, November and December (UV index 2).
Average cloud cover in September
Dale City, VA
- Average cloud cover in September: 37
The month with the most cloud cover is March (Cloud cover 46).
The month with the least cloud cover is July (Cloud cover 30).
Average visibility in September
Dale City, 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).
