July weather forecast
Reston, VA

Share

Weather in July

July is a hot summer month in Reston, Virginia, with temperature in the range of an average high of 87.6°F (30.9°C) and an average low of 68.5°F (20.3°C).

Temperature

Reston notes the warmest temperatures in July, with a high average of 87.6°F (30.9°C) and a low of 68.5°F (20.3°C).

Heat index

The heat index for July is evaluated at a torrid 98.6°F (37°C). Implement additional safety measures to avoid heat cramps and heat exhaustion. Persistent activity might trigger heatstroke.
Bear in mind that the heat index values are determined for shaded areas and light breezes. Direct sunshine exposure could raise heat index values by as much as 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'feels like' or 'felt air temperature', is an estimation of the warmth sensation when considering humidity levels. Depending on the activity and the individual's heat perception, which may vary due to factors including wind, clothing, and metabolic variations, this effect remains subjective. With the sun shining directly, it's crucial to understand that it can increase the heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are quite important for babies and toddlers. Youngsters generally face more threats than adults given their lesser ability to sweat. Coupled with their larger skin surface relative to their small bodies and higher heat production due to their activities, they are more endangered.
To achieve cooling, the human body employs perspiration, relying on the subsequent evaporation of sweat. With excessive moisture in the atmosphere, the effectiveness of the evaporation process is decreased, causing the body to cool down less efficiently, leading to a sensation of overheating. The body is at risk of dehydration and related complications when it fails to shed excessive heat.

Humidity

With an average relative humidity of 69%, July is the least humid month.

Rainfall

In Reston, during July, the rain falls for 15.1 days and regularly aggregates up to 2.68" (68mm) of precipitation. In Reston, during the entire year, the rain falls for 152.8 days and collects up to 27.64" (702mm) of precipitation.

Snowfall

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

Daylight

In July, the average length of the day is 14h and 35min.
On the first day of the month, sunrise is at 5:47 am and sunset at 8:38 pm. On the last day of July, sunrise is at 6:10 am and sunset at 8:21 pm EDT.

Sunshine

July has the most sunshine of the year, with an average of 10.7h of sunshine.

UV index

May through August, with an average maximum UV index of 6, are months with the highest UV index. A UV Index estimate of 6 to 7 represents a high threat to health from unsafe exposure to UV radiation for ordinary individuals.
Note: In July, a daily maximum UV index of 6 leads to the following instructions:
Skirt overexposure. People with light complexions might get scorched in under 20 minutes. The Sun emits the most powerful UV radiation between 10 a.m. and 4 p.m. Try to avoid direct sunlight during this period. Sunglasses that ward off UVA and UVB rays play a pivotal role in reducing solar eye damage.
Updated: Aug 12, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What are the warmest months in Reston?

July is the month that records the highest temperatures, with averages ranging from a high of 87.6°F (30.9°C) to a low of 68.5°F (20.3°C).

How hot is July?

The average high-temperature and low-temperature during July are 87.6°F (30.9°C) and 68.5°F (20.3°C) respectively. In July, the average heat index (a.k.a. 'real feel', 'feels like'), which represents the influence of relative humidity on air temperature, is evaluated at 98.6°F (37°C).

What is the least humid month?

With an average relative humidity of 69%, July is the least humid month.

What is the average humidity in July?

In Reston, the average relative humidity in July is 69%.

How many days does it rain in July?

In Reston, in July, it is raining for 15.1 days, with typically 2.68" (68mm) of accumulated precipitation.

When it does not snow?

May through October are months without snowfall.

How many hours of daylight does Reston have in July?

The average day length in July is 14h and 35min.

When is the sunrise / sunset in July?

On the first day of July, sunrise is at 5:47 am and sunset at 8:38 pm. On the last day of the month, sunrise is at 6:10 am and sunset at 8:21 pm EDT.

What month has the most sunshine in Reston?

July has the most sunshine of the year, with an average of 10.7h of sunshine.

How many hours of sunshine does Reston have in July?

In July, the average sunshine duration in Reston is 10.7h.

What are the months with 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 July in Reston?

The average daily maximum UV index in July is 6. A UV Index estimate of 6 to 7 represents a high hazard to health 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 July
Reston, VA

Average temperature in July - Reston, VA
  • Average high temperature in July: 87.6°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 July: 68.5°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 July
Reston, VA

Average pressure in July - Reston, VA
  • Average pressure in July: 29.97"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 July
Reston, VA

Average wind speed in July - Reston, VA
  • Average wind speed in July: 5mph

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 July
Reston, VA

Average humidity in July - Reston, VA
  • Average humidity in July: 69%

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 July
Reston, VA

Average rainfall in July - Reston, VA
  • Average rainfall in July: 2.68"

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 July
Reston, VA

Average rainfall days in July - Reston, VA
  • Average rainfall days in July: 15.1 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 July
Reston, VA

Average snowfall in July - Reston, VA
  • Average snowfall in July: 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 July
Reston, VA

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

Average daylight in July / Average sunshine in July - Reston, VA
  • Average daylight in July: 14h 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 July: 10h and 4min

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 July
Reston, VA

Average sunshine days in July - Reston, VA
  • Average sunshine days in July: 13.9 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 July
Reston, VA

Average UV index in July - Reston, VA
  • Average UV index in July: 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 July
Reston, VA

Average cloud cover in July - Reston, VA
  • Average cloud cover in July: 31

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 July
Reston, VA

Average visibility in July - Reston, VA
  • Average visibility in July: 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