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
The transition into September involves a small decrease in the average high-temperature, dipping slightly from 85.6°F (29.8°C) in August to a still warm 78.6°F (25.9°C). The temperature lowers to an average of 58.5°F (14.7°C) during September nights.Humidity
The months with the highest humidity are May, September, October and December, with an average relative humidity of 76%.Rainfall
In Commonwealth, in September, during 14.1 rainfall days, 2.05" (52mm) of precipitation is typically accumulated. Throughout the year, there are 155.9 rainfall days, and 27.99" (711mm) of precipitation is accumulated.Snowfall
In Commonwealth, snow does not fall in May through October.Daylight
In September, the average length of the day is 12h and 25min.On the first day of September, sunrise is at 6:44 am and sunset at 7:43 pm. On the last day of the month, sunrise is at 7:09 am and sunset at 6:58 pm EDT.
Sunshine
In September, the average sunshine is 8.7h.UV index
In Commonwealth, the average daily maximum UV index in September is 5. A UV Index reading of 3 to 5 represents a moderate health risk from unsafe exposure to UV radiation for the average person.Note: A maximum high UV index of 5 in September translates into the following recommendations:
Exercise caution. The susceptibility of light skin individuals to burns is less than 30 minutes. When the Sun's UV radiation is most intense during midday, it's best to find shade and limit exposure. Stay sun-safe with clothing that is both closely woven and worn loosely.
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Data Sources | Weather Forecasting & Climate
Frequently asked questions
What are September temperatures in Commonwealth?
What are the most humid months?
What is the average humidity in September?
How much does it rain in Commonwealth in September?
When it does not snow?
What is the average length of the day in September?
What time are sunrise and sunset in September?
How long on average sun shines in September?
What is the UV index intensity in September?
Average temperature in September
Commonwealth, VA
- Average high temperature in September: 78.6°F
The warmest month (with the highest average high temperature) is July (88.2°F).
The month with the lowest average high temperature is January (41.5°F).
- Average low temperature in September: 58.5°F
The month with the highest average low temperature is July (64.6°F).
The coldest month (with the lowest average low temperature) is January (26.1°F).
Average pressure in September
Commonwealth, 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 (29.96"Hg).
Average wind speed in September
Commonwealth, VA
- Average wind speed in September: 4.6mph
The windiest month (with the highest average wind speed) is April (6.3mph).
The calmest month (with the lowest average wind speed) is August (4.2mph).
Average humidity in September
Commonwealth, VA
- Average humidity in September: 76%
The months with the highest relative humidity are May, September, October and December (76%).
The month with the lowest relative humidity is July (71%).
Average rainfall in September
Commonwealth, VA
- Average rainfall in September: 2.05"
The wettest months (with the highest rainfall) are April and May (2.91").
The driest month (with the least rainfall) is January (1.69").
Average rainfall days in September
Commonwealth, VA
- Average rainfall days in September: 14.1 days
The month with the highest number of rainy days is May (17.1 days).
The month with the least rainy days is November (8.9 days).
Average snowfall in September
Commonwealth, VA
- Average snowfall in September: 0"
The month with the highest snowfall is March (3.07").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in September
Commonwealth, VA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (4.6 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
Commonwealth, 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 36min).
- 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 and December (Average sunshine: 5h and 24min).
Average sunshine days in September
Commonwealth, VA
- Average sunshine days in September: 13.8 days
The month with the most sunshine days is December (19.9 days).
The month with the least sunshine days is May (11.4 days).
Average UV index in September
Commonwealth, 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
Commonwealth, VA
- Average cloud cover in September: 39
The month with the most cloud cover is March (Cloud cover 45).
The months with the least cloud cover are June and July (Cloud cover 31).
Average visibility in September
Commonwealth, VA
- Average visibility in September: 5mi
The months with the highest visibility are February, March, April, June, July, August and November (6mi).
The months with the lowest visibility are January, May, September, October and December (5mi).
Commonwealth, Virginia, USA
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