Washington
District of Columbia, USA
Long-term weather forecast
Long-term weather forecast

August weather forecast and climate
Washington, DC

Stunning reflective view of rows of jacaranda trees in spring in the tidal basin of the Washington Monument in DC
Stunning reflective view of rows of jacaranda trees in spring in the tidal basin of the Washington Monument in DC
August, the last month of the summer, in Washington, is another warm month, with temperature in the range of an average low of 68°F (20°C) and an average high of 85.8°F (29.9°C).

Temperature

In Washington, the average high-temperature in August is relatively the same as in July - a moderately hot 85.8°F (29.9°C). In August, in Washington, the average low-temperature is 68°F (20°C).

Heat index

The average heat index is appraised at a very hot 95.5°F (35.3°C). Take extra precautions, as heat cramps and heat exhaustion are possible. Sustained activity may result in heatstroke.
Note that heat index values are valued for light wind and location in the shade. With the exposure to direct sunlight, the heat index may be increased by up to 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'feels like', 'real feel', 'apparent temperature', or 'felt air temperature', is a measure of how hot it feels when the actual air humidity is factored in. Additional factors like activity, clothing, pregnancy, and wind affect individual temperature impact. Be aware that direct exposure to sunlight increases heat impact, and may raise the heat index additionally, by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are especially crucial for babies and toddlers. Young children are generally more endangered than adults, as they usually less sweat. And also, due to larger skin surface relative to their small bodies and higher heat production as a result of their activity.
Perspiration is the human body's physiological response to high temperatures and is an attempt to lower body temperature through evaporation of sweat. High relative humidity reduces the evaporation rate, resulting in a lower heat removal rate from the body, causing the perception of being overheated. If the body can not disperse the excessive heat and body temperature reaches conditions of hyperthermia, above 99.5°F (37.5°C) to 100.9°F (38.3°C), thermal conditions are potentially life-threatening.

Humidity

In August, the average relative humidity is 72%.

Rainfall

August is the month with the most rainfall in Washington. Rain falls for 15.5 days and accumulates 3.46" (88mm) of precipitation.

Snowfall

April through November are months without snowfall in Washington.

Daylight

In Washington, the average length of the day is 13.6h.

Sunshine

In August, the average sunshine in Washington is 10.3h.

UV index

In Washington, the average daily maximum UV index is 6. A UV Index of 6 to 7 symbolizes a high health vulnerability from unsafe exposure to the UV radiation for average individuals.
Note: The daily maximum UV index of 6 in August interpret into the following advice:
Take precautions against overexposure. Fair-skinned people may get burned in less than 20 minutes. Seek shade and minimize exposure to direct Sun in a period between 10 a.m. and 4 p.m. when UV radiation is most intense; keep in mind that shade structures like parasols or canopies do not provide perfect sun protection. A wide-brim hat offers excellent sun protection for eyes, ears, face, and neck. Sunglasses with UVA and UVB protection significantly reduce eye damage from sun exposure. Tightly woven, loose-fitting clothes provide additional protection from the Sun.

What is the temperature in August in Washington?

In August, the average high-temperature is 85.8°F (29.9°C), and the average low-temperature is 68°F (20°C). The average heat index (a.k.a. 'apparent temperature', 'felt air temperature'), that combines both air temperature and relative humidity, in August is appraised at 95.5°F (35.3°C).

What is the average humidity in August in Washington?

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

How much does it rain in Washington in August?

In Washington, District of Columbia, in August, during 15.5 rainfall days, 3.46" (88mm) of precipitation is typically accumulated.

What is the rainiest month in Washington?

The month with the most rainfall is August when the rain falls for 15.5 days and typically aggregates up to 3.46" (88mm) of precipitation.

When it does not snow in Washington?

April through November are months without snowfall in Washington.

What is the average length of the day in August in Washington?

In August, the average length of the day is 13.6h.

How long on average sun shines in August in Washington?

In August, the average sunshine in Washington is 10.3h.

What is the UV index intensity in August in Washington?

In Washington, the average daily maximum UV index in August is 6. A UV Index of 6 to 7 symbolizes a high hazard to health from the exposure to the Sun's UV radiation.
Average temperature in August - Washington, DC
  • 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 (40.6°F).

  • Average low temperature in August: 68°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).

Average humidity in August - Washington, DC
  • Average humidity in August: 72%

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

Average rainfall in August - Washington, DC
  • Average rainfall in August: 3.46"

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

Average rainfall days in August - Washington, DC
  • Average rainfall days in August: 15.5 days

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

Average snowfall in August - Washington, DC
  • Average snowfall in August: 0"

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

Average snowfall days in August - Washington, DC
  • Average snowfall days in August: 0 days

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

Average daylight in August / Average sunshine in August - Washington, DC
  • Average daylight in August: 13.6h

The month with the longest days is June (Average daylight: 14.9h).
The month with shortest days is December (Average daylight: 9.5h).

  • Average sunshine in August: 10.3h

The month with most sunshine is July (Average sunshine: 10.7h).
Months with least sunshine are January, February and December (Average sunshine: 5.1).

Average UV index in August - Washington, DC
  • Average UV index in August: 6

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