July weather forecastMcLean, VA
July
Weather in July
July is a hot summer month in McLean, Virginia, with an average temperature fluctuating between 69.1°F (20.6°C) and 87.4°F (30.8°C).Temperature
During the warmest month, July, temperatures average a high of 87.4°F (30.8°C) and a low of 69.1°F (20.6°C).Heat index
For July, the heat index is appraised at a sweltering 98.6°F (37°C). Adopt heightened preventive measures, heat exhaustion and heat cramps are probable. Persistent activity could lead to heatstroke.The standards for the heat index are set for locations in shade and under light breezes. If exposed to direct sunlight, the heat index could climb by up to 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'apparent temperature' or 'felt air temperature', is a measure that combines air temperature and relative humidity into a single value that indicates how hot the weather feels. Elements such as metabolic variations, pregnancy, and physical exertion can shape one's weather perception. Given the impact of direct sunlight, it's noteworthy that the felt temperature can rise by 15 Fahrenheit (8 Celsius) degrees. Heat index values hold particular importance for children. Youngsters frequently overlook the need for breaks and fluid intake. Thirst is an advanced sign of dehydration - thereby highlighting the importance of keeping hydrated, particularly during long physical activities.
Perspiration is the human body's physiological response to high temperatures and is an attempt to lower body temperature through evaporation of sweat. During conditions of high air temperature and humidity (high heat index), the body's ability to perspire is inhibited, increasing the sensation of warmth. Elevated heat gain compared to the body's release capability poses risks of dehydration and potential overheating.
Humidity
With an average relative humidity of 70%, July is the least humid month.Rainfall
In July, the rain falls for 13.5 days. Throughout July, 1.18" (30mm) of precipitation is accumulated. In McLean, during the entire year, the rain falls for 109 days and collects up to 9.29" (236mm) of precipitation.Snowfall
In McLean, snow does not fall in May through October.Daylight
The average length of the day in July 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 6:09 am and sunset at 8:20 pm EDT.
Sunshine
With an average of 10.9h of sunshine, July has the most sunshine of the year.UV index
May through August, with an average maximum UV index of 6, are months with the highest UV index. A UV Index of 6 to 7 symbolizes a high health hazard from exposure to the Sun's UV radiation for average individuals.Note: A maximum high UV index of 6 in July translates into the following recommendations:
Ward off overexposure. Defence against solar harm is crucial. Stay in the shade and limit sun exposure from 10 a.m. to 4 p.m., when UV radiation is most potent. Keep in mind that shade structures like parasols or canopies do not offer full protection. Fend off the sun's harsh rays with appropriate clothing, a wide-brim hat, and UV-protective sunglasses.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in July
McLean, VA
- Average high temperature in July: 87.4°F
The warmest month (with the highest average high temperature) is July (87.4°F).
The month with the lowest average high temperature is January (40.1°F).
- Average low temperature in July: 69.1°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 (26.8°F).
Average pressure in July
McLean, 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
McLean, 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
McLean, VA
- Average humidity in July: 70%
The months with the highest relative humidity are October and December (76%).
The month with the lowest relative humidity is July (70%).
Average rainfall in July
McLean, VA
- Average rainfall in July: 1.18"
The wettest month (with the highest rainfall) is August (1.5").
The driest months (with the least rainfall) are January and September (0.51").
Average rainfall days in July
McLean, VA
- Average rainfall days in July: 13.5 days
The month with the highest number of rainy days is July (13.5 days).
The month with the least rainy days is November (5.6 days).
Average snowfall in July
McLean, VA
- Average snowfall in July: 0"
The month with the highest snowfall is January (0.98").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in July
McLean, VA
- Average snowfall days in July: 0 days
The month with the highest number of snowfall days is February (3.6 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
McLean, VA
- Average daylight in July: 14h and 36min
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 54min
The month with the most sunshine is July (Average sunshine: 10h and 54min).
The months with the least sunshine are February and December (Average sunshine: 5h and 6min).
Average sunshine days in July
McLean, VA
- Average sunshine days in July: 14.3 days
The month with the most sunshine days is November (23 days).
The month with the least sunshine days is July (14.3 days).
Average UV index in July
McLean, 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, November and December (UV index 2).
Average cloud cover in July
McLean, VA
- Average cloud cover in July: 30
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 July
McLean, 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).
