Contents
- Weather in September
- Frequently asked questions
- Average temperature in September
- Average pressure in September
- Average wind speed in September
- Average humidity in September
- Average rainfall in September
- Average rainfall days in September
- Average snowfall in September
- Average snowfall days in September
- Average daylight in September
- Average sunshine in September
- Average sunshine days in September
- Average UV index in September
- Average cloud cover in September
- Average visibility in September
Weather in September
Temperature
September brings a slight decrease in the average high-temperature, shifting from a tropical 86°F (30°C) in August to a warm 79.2°F (26.2°C). During September, Dale City's temperature falls to a steady low-temperature average of 61°F (16.1°C).Humidity
In Dale City, the average relative humidity in September is 76%.Rainfall
In September, in Dale City, the rain falls for 8.8 days. Throughout September, 0.51" (13mm) of precipitation is accumulated. In Dale City, during the entire year, the rain falls for 105.2 days and collects up to 9.21" (234mm) of precipitation.Snowfall
May through October are months without snowfall.Daylight
In September, the average length of the day in Dale City 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, in Dale City, Virginia, 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 threat to health from unsafe exposure to UV radiation for average individuals.Note: In September, an average UV index of 5 transforms into the following instructions:
Heed the precautions - It is counselled to guard against solar damage. Solar radiation is at its peak intensity during midday, so it's advisable to stay indoors or in the shade. Shield yourself from the harmful effects of UV radiation with sun-protective attire, a hat, and quality sunglasses.
Frequently asked questions
What is the average September temperature in Dale City?
What is the average humidity in September in Dale City?
How much does it rain in Dale City in September?
When it does not snow in Dale City?
What is the average length of the day in September in Dale City?
When is the sunrise / sunset in September in Dale City?
How long on average sun shines in September in Dale City?
What is the UV index reading in September in Dale City?
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 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 5min
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).
Dale City, Virginia, USA
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