September weather forecast
Arlington, VA

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Weather in September

The arrival of September brings a significant change in Arlington's weather, hinting at the approaching fall season. The temperatures begin to descend from the summer highs, and the daylight hours gradually decrease. Despite these changes, people can still enjoy outdoor activities as rainfall reduces considerably from the previous months. It is also noteworthy that wind speed increases lightly, marking the beginning of autumn.

Temperature

In the transition to September, Arlington observes a minor drop in the average high-temperature, shifting from 85.8°F in August to a still warm 78.4°F. During September, Arlington experiences an average low-temperature of 61.9°F at night.

Humidity

In September, the average relative humidity in Arlington is 74%.

Rainfall

In Arlington, in September, during 12.5 rainfall days, 1.85" of precipitation is typically accumulated. Throughout the year, in Arlington, there are 149.1 rainfall days, and 26.14" of precipitation is accumulated.

Snowfall

April through November are months without snowfall in Arlington.

Daylight

In September, the average length of the day in Arlington is 12h and 26min.
On the first day of the month, sunrise is at 6:37 am and sunset at 7:39 pm. On the last day of September, sunrise is at 7:03 am and sunset at 6:53 pm EDT.

Sunshine

In Arlington, the average sunshine in September is 9h.

UV index

The average daily maximum UV index in September in Arlington is 5. A UV Index estimate of 3 to 5 represents a moderate health risk from unprotected exposure to Sun's UV rays for average individuals.
Note: In September, the maximum UV index of 5 suggests these recommendations:
Preventative actions are necessary - The mandate to avoid skin and eye damage is in place. Exposing oneself to the midday Sun can be harmful due to the strong UV radiation; limit your time outside. It's wise to wear UVA and UVB-blocking sunglasses when the sun shines brightly.
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FAQ

What is the temperature in September in Arlington?

In Arlington, in September, the average high-temperature is 78.4°F, and the average low-temperature is 61.9°F. In August, the average heat index (a.k.a. 'real feel', 'apparent temperature'), which factors the actual air temperature with the relative humidity, is evaluated at 95°F.

What is the average humidity in September in Arlington?

In September, the average relative humidity in Arlington, Virginia, is 74%.

How much does it rain in Arlington in September?

In Arlington, Virginia, during September, the rain falls for 12.5 days and regularly aggregates up to 1.85" of precipitation.

When it does not snow in Arlington?

April through November are months without snowfall in Arlington.

How many hours of daylight does Arlington have in September?

In September, the average day length in Arlington, Virginia, is 12h and 26min.

When is the sunrise / sunset in September in Arlington?

In September, on the first day of the month, sunrise is at 6:37 am and sunset at 7:39 pm. On the last day of the month, sunrise is at 7:03 am and sunset at 6:53 pm EDT.

How long on average sun shines in September in Arlington?

In Arlington, the average sunshine duration in September is 9h.

What is the UV index intensity in September in Arlington?

The average daily maximum UV index in September in Arlington, Virginia, is 5. A UV Index value of 3 to 5 symbolizes a moderate vulnerability from exposure to the Sun's UV radiation.
Average high temperature
Average low temperature
Average pressure
Average wind speed
Average max. wind speed
Average wind speed gusts
Average humidity
Average rainfall
Average rainfall days
Average snowfall
Average snowfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in September
Arlington, VA

Average temperature in September - Arlington, VA
  • Average high temperature in September: 78.4°F

The warmest month (with the highest average high temperature) is July (88°F).
The month with the lowest average high temperature is January (40.6°F).

  • Average low temperature in September: 61.9°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 (27.5°F).

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Average pressure in September
Arlington, VA

Average pressure in September - Arlington, 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).

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Average wind speed in September
Arlington, VA

Average wind speed in September - Arlington, VA
  • Average wind speed in September: 5.7mph

The windiest month (with the highest average wind speed) is March (7.9mph).
The calmest month (with the lowest average wind speed) is August (5mph).

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Average humidity in September
Arlington, VA

Average humidity in September - Arlington, VA
  • Average humidity in September: 74%

The month with the highest relative humidity is May (76%).
The months with the lowest relative humidity are April and July (71%).

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Average rainfall in September
Arlington, VA

Average rainfall in September - Arlington, VA
  • Average rainfall in September: 1.85"

The wettest month (with the highest rainfall) is August (3.46").
The driest month (with the least rainfall) is January (1.57").

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Average rainfall days in September
Arlington, VA

Average rainfall days in September - Arlington, VA
  • Average rainfall days in September: 12.5 days

The month with the highest number of rainy days is July (16.4 days).
The month with the least rainy days is November (8.1 days).

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Average snowfall in September
Arlington, VA

Average snowfall in September - Arlington, VA
  • Average snowfall in September: 0"

The month with the highest snowfall is January (2.17").
The months with the least snowfall are April, May, June, July, August, September, October and November (0").

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Average snowfall days in September
Arlington, VA

Average snowfall days in September - Arlington, VA
  • Average snowfall days in September: 0 days

The months with the highest number of snowfall days are January and February (3.8 days).
The months with the least snowfall days are April, May, June, July, August, September and October (0 days).

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Average daylight in September /
Average sunshine in September
Arlington, VA

Average daylight in September / Average sunshine in September - Arlington, 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 0min

The month with the most sunshine is July (Average sunshine: 10h and 42min).
The months with the least sunshine are January, February and December (Average sunshine: 5h and 6min).

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Average sunshine days in September
Arlington, VA

Average sunshine days in September - Arlington, VA
  • Average sunshine days in September: 15.7 days

The month with the most sunshine days is November (20 days).
The month with the least sunshine days is May (12.8 days).

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Average UV index in September
Arlington, VA

Average UV index in September - Arlington, VA
  • Average UV index in September: 5

The month with the highest UV index is June (UV index 7).
The months with the lowest UV index are January and December (UV index 2).

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Average cloud cover in September
Arlington, VA

Average cloud cover in September - Arlington, 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).

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Average visibility in September
Arlington, VA

Average visibility in September - Arlington, 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).

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Arlington, Virginia, USA

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