September weather forecastSwimley, VA
September
Weather in September
September, the first month of the autumn in Swimley, is still a warm month, with an average temperature fluctuating between 77°F (25°C) and 56.8°F (13.8°C).Temperature
The arrival of September corresponds with a light shift in temperature, down from 84.4°F (29.1°C) in August to a still moderately hot 77°F (25°C). An average temperature of 56.8°F (13.8°C) marks the nights in September.Humidity
In Swimley, the average relative humidity in September is 77%.Rainfall
In September, the rain falls for 12.9 days. Throughout September, 1.61" (41mm) of precipitation is accumulated. In Swimley, during the entire year, the rain falls for 152.4 days and collects up to 23.5" (597mm) of precipitation.Snowfall
June through September are months without snowfall.Daylight
In Swimley, the average length of the day in September is 12h and 26min.On the first day of September, sunrise is at 6:41 am and sunset at 7:42 pm. On the last day of the month, sunrise is at 7:07 am and sunset at 6:55 pm EDT.
Sunshine
The average sunshine in September is 8.8h.UV index
In Swimley, Virginia, the average daily maximum UV index in September is 4. A UV Index reading of 3 to 5 represents a moderate threat to health from unprotected exposure to Sun's UV rays for ordinary individuals.Note: The daily maximum UV index of 4 in September interprets into the following advice:
Take heed. Individuals of lighter complexion can be burned in less than half an hour. The Sun is most powerful around mid-day, so it's a good practice to reduce direct exposure. Combat UV radiation's detrimental effects with sun-safe clothing and UV-blocking eyewear.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Swimley, VA
- Average high temperature in September: 77°F
The warmest month (with the highest average high temperature) is July (86.5°F).
The month with the lowest average high temperature is January (38.3°F).
- Average low temperature in September: 56.8°F
The month with the highest average low temperature is July (64.4°F).
The coldest month (with the lowest average low temperature) is January (24.1°F).
Average pressure in September
Swimley, VA
- Average pressure in September: 30.06"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
Swimley, VA
- Average wind speed in September: 4.8mph
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 (4.3mph).
Average humidity in September
Swimley, VA
- Average humidity in September: 77%
The months with the highest relative humidity are May, October and December (78%).
The month with the lowest relative humidity is July (73%).
Average rainfall in September
Swimley, VA
- Average rainfall in September: 1.61"
The wettest months (with the highest rainfall) are May, July and August (2.68").
The driest month (with the least rainfall) is January (1.3").
Average rainfall days in September
Swimley, VA
- Average rainfall days in September: 12.9 days
The month with the highest number of rainy days is May (17.3 days).
The month with the least rainy days is January (7.9 days).
Average snowfall in September
Swimley, VA
- Average snowfall in September: 0"
The month with the highest snowfall is January (2.68").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Swimley, VA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (6.9 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Swimley, 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 48min
The month with the most sunshine is July (Average sunshine: 10h and 36min).
The months with the least sunshine are January and December (Average sunshine: 5h and 0min).
Average sunshine days in September
Swimley, VA
- Average sunshine days in September: 15.1 days
The month with the most sunshine days is November (19.4 days).
The month with the least sunshine days is May (11.5 days).
Average UV index in September
Swimley, VA
- Average UV index in September: 4
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
Swimley, VA
- Average cloud cover in September: 38
The months with the most cloud cover are March and December (Cloud cover 47).
The month with the least cloud cover is July (Cloud cover 30).
Average visibility in September
Swimley, 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).
