August weather forecast
Vienna, VA

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Weather in August

August, the last month of the summer in Vienna, is another warm month, with an average temperature varying between 66.9°F (19.4°C) and 85.8°F (29.9°C).

Temperature

As Vienna steps into August, the average high-temperature is measured at a moderately hot 85.8°F (29.9°C), displaying minor differences from July's 88°F (31.1°C). An average low-temperature of 66.9°F (19.4°C) is noted during the month of August.

Heat index

For August, the heat index is calculated to be a sweltering 95°F (35°C). Exercise increased caution, heat cramps and heat exhaustion are potential hazards. Continuous activity could lead to heatstroke.
One should be cognizant that the heat index values are tailored for shaded spots and mild winds. Heat index values may be hiked up by 15 Fahrenheit (8 Celsius) degrees under direct sunshine.
Note: The heat index, also known as 'feels like' or 'felt air temperature', is achieved by amalgamating air temperature with the relative humidity readings. The perception of temperature can be subjective, varying based on activity and individual heat sensitivity, influenced by factors like wind, attire, and metabolic variations. Take note that direct exposure to the sun can increase the felt temperature, possibly adding 15 Fahrenheit (8 Celsius) degrees to the heat index. Heat index values are especially vital to children. Young ones often underestimate the need for rest and rehydration. Thirst appears late in dehydration - hence, it is important to keep hydrated, particularly during prolonged physical activities.
By perspiring, the human body can shed its excessive warmth since evaporated sweat cools it off. In situations of high air temperature combined with high humidity (significant heat index), the body's ability to perspire is reduced, heightening the sense of warmth. Heat-related disorders may develop if heat gain in the body overshadows its cooling capacity, leading to elevated temperatures.

Humidity

In Vienna, the average relative humidity in August is 72%.

Rainfall

The month with the most rainfall is August, when the rain falls for 17.3 days and typically aggregates up to 3.78" (96mm) of precipitation.

Snowfall

In Vienna, snow does not fall in May through October.

Daylight

In August, the average length of the day in Vienna is 13h and 38min.
On the first day of August, sunrise is at 6:10 am and sunset at 8:20 pm. On the last day of the month, sunrise is at 6:37 am and sunset at 7:40 pm EDT.

Sunshine

In August, the average sunshine is 10.2h.

UV index

The months with the highest UV index are May through August, with an average maximum UV index of 6. A UV Index reading of 6 to 7 represents a high health vulnerability from exposure to the Sun's UV rays for the ordinary person.
Note: An average UV index of 6 in August transforms into this advice:
Fend off overexposure. Sun protection is vital. The Sun's UV radiation is most potent between the hours of 10 a.m. and 4 p.m. Try to avoid direct sunlight during this time. Employ a wide-brim hat for potent defense against up to 50% of UV rays.

Frequently asked questions

How hot is August?

During August, Vienna experiences an average high-temperature of 85.8°F (29.9°C) and a low-temperature of 66.9°F (19.4°C). In August, the average heat index (a.k.a. 'feels like', 'real feel'), which takes the relative humidity and factors it into the air temperature reading, is calculated to be 95°F (35°C).

What is the average humidity in August?

In August, the average relative humidity is 72%.

What is the wettest month?

August is the month with the most rainfall. Rain falls for 17.3 days and accumulates 3.78" (96mm) of precipitation.

How much does it rain in August?

In Vienna, during August, the rain falls for 17.3 days and regularly aggregates up to 3.78" (96mm) of precipitation.

When it does not snow?

May through October are months without snowfall.

How many hours of daylight does Vienna have in August?

The average day length in August is 13h and 38min.

When are sunrise and sunset in August?

In August, on the first day of the month, sunrise is at 6:10 am and sunset at 8:20 pm. On the last day of the month, sunrise is at 6:37 am and sunset at 7:40 pm EDT.

How many hours of sunshine does Vienna have in August?

In Vienna, the average sunshine duration in August is 10.2h.

When is the highest UV index?

May through August, with an average maximum UV index of 6, are months with the highest UV index.

How high is the UV index in August?

The average daily maximum UV index in August is 6. A UV Index value of 6 to 7 symbolizes a high health threat from unprotected exposure to UV radiation.
Average humidity
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 August
Vienna, VA

Average temperature in August - Vienna, VA
  • Average high temperature in August: 85.8°F

The warmest month (with the highest average high temperature) is July (88°F).
The month with the lowest average high temperature is January (40.5°F).

  • Average low temperature in August: 66.9°F

The month with the highest average low temperature is July (68.4°F).
The coldest month (with the lowest average low temperature) is January (26.4°F).

Average pressure in August
Vienna, VA

Average pressure in August - Vienna, VA
  • Average pressure in August: 29.99"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 August
Vienna, VA

Average wind speed in August - Vienna, VA
  • Average wind speed in August: 4.7mph

The windiest month (with the highest average wind speed) is March (7.4mph).
The calmest month (with the lowest average wind speed) is August (4.7mph).

Average humidity in August
Vienna, VA

Average humidity in August - Vienna, VA
  • Average humidity in August: 72%

The months with the highest relative humidity are October and December (77%).
The month with the lowest relative humidity is July (71%).

Average rainfall in August
Vienna, VA

Average rainfall in August - Vienna, VA
  • Average rainfall in August: 3.78"

The wettest month (with the highest rainfall) is August (3.78").
The driest month (with the least rainfall) is September (2.01").

Average rainfall days in August
Vienna, VA

Average rainfall days in August - Vienna, VA
  • Average rainfall days in August: 17.3 days

The months with the highest number of rainy days are May and August (17.3 days).
The month with the least rainy days is November (9.1 days).

Average snowfall in August
Vienna, VA

Average snowfall in August - Vienna, VA
  • Average snowfall in August: 0"

The month with the highest snowfall is January (3.54").
The months with the least snowfall are May, June, July, August, September and October (0").

Average snowfall days in August
Vienna, VA

Average snowfall days in August - Vienna, VA
  • Average snowfall days in August: 0 days

The month with the highest number of snowfall days is January (5.6 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).

Average daylight in August /
Average sunshine in August
Vienna, VA

Average daylight in August / Average sunshine in August - Vienna, VA
  • Average daylight in August: 13h and 4min

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 August: 10h and 1min

The month with the most sunshine is July (Average sunshine: 10h and 48min).
The months with the least sunshine are January, February and December (Average sunshine: 5h and 12min).

Average sunshine days in August
Vienna, VA

Average sunshine days in August - Vienna, VA
  • Average sunshine days in August: 11.6 days

The month with the most sunshine days is November (19.6 days).
The month with the least sunshine days is July (11.3 days).

Average UV index in August
Vienna, VA

Average UV index in August - Vienna, VA
  • Average UV index in August: 6

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 August
Vienna, VA

Average cloud cover in August - Vienna, VA
  • Average cloud cover in August: 33

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 August
Vienna, VA

Average visibility in August - Vienna, VA
  • Average visibility in August: 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).

Vienna, Virginia, USA

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