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
Merrifield's September weather features a light decline in high-temperatures, reducing from 85.6°F (29.8°C) in August to a still moderately hot 78.6°F (25.9°C). An average minimum temperature of 61.3°F (16.3°C) marks the month of September in Merrifield, Virginia.Humidity
In Merrifield, Virginia, the average relative humidity in September is 74%.Rainfall
In Merrifield, Virginia, in September, during 12.7 rainfall days, 2.09" (53mm) of precipitation is typically accumulated. Throughout the year, in Merrifield, there are 161.2 rainfall days, and 31.54" (801mm) of precipitation is accumulated.Snowfall
In Merrifield, Virginia, snow does not fall in May through October.Daylight
The average length of the day in September is 12h and 26min.On the first day of the month, sunrise is at 6:38 am and sunset at 7:38 pm. On the last day of September, sunrise is at 7:04 am and sunset at 6:52 pm EDT.
Sunshine
The average sunshine in September is 9.1h.UV index
The average daily maximum UV index in September in Merrifield is 5. A UV Index value of 3 to 5 symbolizes a medium health hazard from unprotected exposure to Sun's UV rays for the ordinary person.Note: In September, the maximum UV index of 5 suggests these recommendations:
Adopt protective measures - Requirement to safeguard skin and eyes from harm exists. For health reasons, it's advisable to reduce direct sun exposure during peak hours around midday. For effective sun eye protection, rely on sunglasses certified for UVA and UVB resistance.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What are September temperatures in Merrifield?
What is the average humidity in September in Merrifield?
How many days does it rain in September in Merrifield?
When it does not snow in Merrifield?
What is the average length of the day in September in Merrifield?
When are sunrise and sunset in September in Merrifield?
How long on average sun shines in September in Merrifield?
What is the UV index intensity in September in Merrifield?
Average temperature in September
Merrifield, VA
- Average high temperature in September: 78.6°F
The warmest month (with the highest average high temperature) is July (87.6°F).
The month with the lowest average high temperature is January (40.5°F).
- Average low temperature in September: 61.3°F
The month with the highest average low temperature is July (69.1°F).
The coldest month (with the lowest average low temperature) is January (27.1°F).
Average pressure in September
Merrifield, 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
Merrifield, VA
- Average wind speed in September: 5.4mph
The windiest month (with the highest average wind speed) is March (7.6mph).
The calmest month (with the lowest average wind speed) is August (4.8mph).
Average humidity in September
Merrifield, VA
- Average humidity in September: 74%
The month with the highest relative humidity is October (77%).
The months with the lowest relative humidity are April and July (71%).
Average rainfall in September
Merrifield, VA
- Average rainfall in September: 2.09"
The wettest month (with the highest rainfall) is August (3.78").
The driest month (with the least rainfall) is January (2.05").
Average rainfall days in September
Merrifield, VA
- Average rainfall days in September: 12.7 days
The month with the highest number of rainy days is May (18.2 days).
The month with the least rainy days is November (8.9 days).
Average snowfall in September
Merrifield, VA
- Average snowfall in September: 0"
The month with the highest snowfall is January (3.31").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in September
Merrifield, VA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (4.9 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
Merrifield, 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: 9h and 1min
The month with the most sunshine is July (Average sunshine: 10h and 54min).
The months with the least sunshine are January, February and December (Average sunshine: 5h and 12min).
Average sunshine days in September
Merrifield, VA
- Average sunshine days in September: 15.6 days
The month with the most sunshine days is November (19.2 days).
The month with the least sunshine days is July (10.9 days).
Average UV index in September
Merrifield, 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
Merrifield, VA
- Average cloud cover in September: 36
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
Merrifield, 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).
Merrifield, Virginia, USA
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