August Weather in Washington, United States

Last updated: June 24, 2025

In Washington, United States, the average temperature in August hovers around 19°C (67°F). Expect a comfortable range with minimums dipping to 4°C (40°F) and maximums reaching up to 32°C (91°F). During this month, you'll likely encounter around 98 mm (3.9 in) of precipitation over approximately 13 days, with humidity averaging at 64%.

August Temperature in Washington

In August, in Washington, the average temperature is 19°C (67°F). The maximum can reach 32°C (91°F), while the minimum can be as low as 4°C (40°F). This diverse temperature range makes it a perfect time for travelers to experience both warm and cool days while exploring the area.

August Weather in Washington: Daily Temperature Highs, Lows, and Averages

The chart illustrates August temperature patterns in Washington, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Washington, August typically has an average temperature of 19°C (67°F), with highs reaching up to 32°C (91°F) and lows dropping to around 4°C (40°F).

Data source: Temperature data for Washington generated using information from the Copernicus Climate Change Service.

August Precipitation in Washington

In Washington in August, the precipitation amount is 98 mm (3.9 in) over a span of 13 days.

August Precipitation Trends in Washington

The chart displays monthly precipitation patterns in Washington, with values for each month alongside August’s data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how August’s conditions compare to those of other months. In Washington, August typically receives around 98 mm (3.9 inches) of precipitation spread over approximately 13 days.

Data source: Precipitation data for August generated using information from the Copernicus Climate Change Service.

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Millimeters (mm) Inches (in)

August Humidity in Washington

In Washington in August, humidity is 64%. With an average temperature of 19°C (67°F), this humidity feels like a warm, sultry embrace, perfect for leisurely strolls and exploring local sights, though travelers should stay hydrated and take breaks in shaded areas to fully enjoy the vibrant atmosphere.

August Average Humidity in Washington

This chart illustrates the average monthly humidity levels in Washington, with August’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In August, average humidity in Washington is approximately 64%, offering insight into how humid the weather typically is during this month.

Data source: Humidity data for August generated using information from the Copernicus Climate Change Service.

August UV Index in Washington

In Washington in August, the maximum UV index is 9, which corresponds to a very high Exposure Category. The time to burn is just 15 minutes, so it's essential to take precautions. For detailed information, you can check the Hourly UV Index in Washington.

Maximum UV Index Levels in Washington for August

The chart shows the monthly maximum UV Index (UVI) for Washington in August, representing the highest UV radiation level. The UVI measures the intensity of ultraviolet radiation from the sun, indicating the potential risk of sunburn and UV-related health issues. In August, the maximum UV index in Washington typically reaches 9, which falls under the very high exposure category.

Data source: Washington August UVI data generated using information from the Copernicus Climate Change Service.

UV Risk Categories

Extreme (11+): Avoid the sun, stay in shade.
Very High (8-10): Limit sun exposure.
High (6-7): Use SPF 30+ and protective clothing.
Moderate (3-5): Midday shade recommended.
Low (0-2): No protection needed.

How August Weather in Washington Compares to Other Months

Weather in Washington varies notably across the year, with each month offering distinct climate conditions. This page compares August’s weather to other months in Washington, focusing on differences in temperature, rainfall, humidity, and UV levels.

This table compares monthly weather conditions in Washington, showing how August’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	-7°C (19°F)	77 mm (3.0 inches)	89%	low
February Weather	-6°C (22°F)	80 mm (3.2 inches)	88%	moderate
March Weather	-2°C (29°F)	71 mm (2.8 inches)	86%	moderate
April Weather	5°C (42°F)	117 mm (4.6 inches)	84%	very high
May Weather	12°C (55°F)	96 mm (3.8 inches)	76%	very high
June Weather	17°C (64°F)	97 mm (3.8 inches)	72%	very high
July Weather	20°C (69°F)	140 mm (5.5 inches)	66%	very high
August Weather	19°C (67°F)	98 mm (3.9 inches)	64%	very high
September Weather	15°C (60°F)	71 mm (2.8 inches)	72%	high
October Weather	9°C (48°F)	141 mm (5.6 inches)	81%	moderate
November Weather	1°C (33°F)	104 mm (4.1 inches)	87%	moderate
December Weather	-5°C (24°F)	88 mm (3.4 inches)	84%	low