August weather forecast
Reston, VA

Share

Weather in August

August, the last month of the summer in Reston, is also a moderately hot month, with temperature in the range of an average low of 67.3°F (19.6°C) and an average high of 85.6°F (29.8°C).

Temperature

The onset of August brings an average high-temperature of a warm 85.6°F (29.8°C), nearly matching the July temperature. Throughout August nights, Reston registers an average low-temperature of 67.3°F (19.6°C).

Heat index

For August, the heat index is evaluated at a torrid 95°F (35°C). Implement additional safety measures to avoid heat cramps and heat exhaustion. Persistent activity might trigger heatstroke.
Know that the heat index computations account for shaded terrains and slight winds. Exposure to direct sunlight may make the heat index values climb by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'apparent temperature' or 'real feel', is achieved by amalgamating air temperature with the relative humidity readings. The influence of weather is personal, with a diverse population experiencing it differently due to differences in body mass, stature, and degree of activity. It is important to note that direct sunlight can intensify the weather impact, potentially raising the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values hold particular significance for children. Children often overlook the need for breaks and fluid intake. Thirst is a late-stage sign of dehydration - hence, it is necessary to stay hydrated, especially during extended periods of physical activities.
When temperatures rise, the human body turns to perspiration, using the cooling power of evaporating sweat. Augmented relative humidity impedes typical body cooling mechanisms by lowering the evaporation rate, resulting in decreased body cooling and an amplified perception of heat. Excessive heat that's not properly managed leads to increased body temperatures and resultant health issues.

Humidity

In Reston, the average relative humidity in August is 71%.

Rainfall

The month with the most rainfall is August, when the rain falls for 15.6 days and typically aggregates up to 3.39" (86mm) of precipitation.

Snowfall

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

Daylight

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

Sunshine

In Reston, Virginia, the average sunshine in August 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 of 6 to 7 symbolizes a high health risk from exposure to the Sun's UV radiation for average individuals.
Note: In August, a daily UV index of 6 turns into the following recommendations:
Sustain precautions and conform to sun safety norms. Preventing sunburn is necessary. Remember that the sun's UV radiation is strongest between 10 a.m. and 4 p.m. Make an effort to avoid direct sun exposure during these hours. Shield yourself from the harmful effects of UV radiation with sun-protective attire, a hat, and quality sunglasses.
Updated: Aug 12, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

How hot is it in August?

The high-temperature, in August, in Reston, records 85.6°F (29.8°C), while the low-temperature is 67.3°F (19.6°C). The average heat index (a.k.a. 'apparent temperature', 'felt air temperature'), which combines relative humidity and air temperature, in August is evaluated at 95°F (35°C).

What is the average humidity in August?

In Reston, the average relative humidity in August is 71%.

What is the wettest month?

August is the month with the most rainfall. Rain falls for 15.6 days and accumulates 3.39" (86mm) of precipitation.

How many days does it rain in August?

In Reston, in August, it is raining for 15.6 days, with typically 3.39" (86mm) of accumulated precipitation.

When it does not snow?

May through October are months without snowfall in Reston.

How many hours of daylight does Reston have in August?

In Reston, the average day length in August is 13h and 38min.

What time 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 6:38 am and sunset at 7:40 pm EDT.

How many hours of sunshine does Reston have in August?

The average sunshine duration in August is 10.2h.

When is the highest UV index?

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

What is the UV index reading in August in Reston?

In August, the average daily maximum UV index is 6. A UV Index value of 6 to 7 symbolizes a high health threat from exposure to the Sun's 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
Reston, VA

Average temperature in August - Reston, VA
  • Average high temperature in August: 85.6°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 (39.7°F).

  • Average low temperature in August: 67.3°F

The month with the highest average low temperature is July (68.5°F).
The coldest month (with the lowest average low temperature) is January (26.4°F).

Average pressure in August
Reston, VA

Average pressure in August - Reston, 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
Reston, VA

Average wind speed in August - Reston, VA
  • Average wind speed in August: 4.9mph

The windiest month (with the highest average wind speed) is March (7.7mph).
The calmest month (with the lowest average wind speed) is August (4.9mph).

Average humidity in August
Reston, VA

Average humidity in August - Reston, VA
  • Average humidity in August: 71%

The months with the highest relative humidity are October and December (76%).
The month with the lowest relative humidity is July (69%).

Average rainfall in August
Reston, VA

Average rainfall in August - Reston, VA
  • Average rainfall in August: 3.39"

The wettest month (with the highest rainfall) is August (3.39").
The driest month (with the least rainfall) is January (1.77").

Average rainfall days in August
Reston, VA

Average rainfall days in August - Reston, VA
  • Average rainfall days in August: 15.6 days

The month with the highest number of rainy days is May (16.3 days).
The month with the least rainy days is November (9.3 days).

Average snowfall in August
Reston, VA

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

The month with the highest snowfall is January (2.28").
The months with the least snowfall are May, June, July, August, September and October (0").

Average snowfall days in August
Reston, VA

Average snowfall days in August - Reston, VA
  • Average snowfall days in August: 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 August /
Average sunshine in August
Reston, VA

Average daylight in August / Average sunshine in August - Reston, 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 42min).
The months with the least sunshine are January, February and December (Average sunshine: 5h and 0min).

Average sunshine days in August
Reston, VA

Average sunshine days in August - Reston, VA
  • Average sunshine days in August: 14.2 days

The month with the most sunshine days is November (19.3 days).
The month with the least sunshine days is May (12.8 days).

Average UV index in August
Reston, VA

Average UV index in August - Reston, 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
Reston, VA

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

The month with the most cloud cover is March (Cloud cover 47).
The month with the least cloud cover is July (Cloud cover 31).

Average visibility in August
Reston, VA

Average visibility in August - Reston, 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).

Reston, Virginia, USA

Weather forecast for your location

1. Click Locate me button
2. Allow the app to use your location