August Weather in Washington, United States

Last updated: June 24, 2025

In Washington, United States, the average temperature in August hovers around 25°C (77°F), creating a comfortable climate. However, be prepared for fluctuations, as temperatures can dip to a cool 11°C (53°F) or soar to a hot 37°C (98°F). With an average of 95 mm (3.7 in) of precipitation over 9 days, it's wise to keep an umbrella handy. The average humidity is a notable 78%, adding a touch of tropical warmth to this vibrant locale.

August Temperature in Washington

In August in Washington, the average temperature is 25°C (77°F), with maximums reaching up to 37°C (98°F) and minimums dropping as low as 11°C (53°F). This makes it an ideal time for travelers to enjoy warm days while also being prepared for cooler evenings.

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 25°C (77°F), with highs reaching up to 37°C (98°F) and lows dropping to around 11°C (53°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 95 mm (3.7 in) over the course of 9 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 95 mm (3.7 inches) of precipitation spread over approximately 9 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 78%. With an average temperature of 25°C (77°F), this humidity feels like walking through a warm, damp blanket, making travel feel a bit more exhausting and sticky as you navigate the sights.

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 78%, 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 reaches 10, which corresponds to a very high Exposure Category. With a time to burn of just 15 minutes, it's crucial to take precautions. For more 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 10, 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	-1°C (30°F)	28 mm (1.1 inches)	76%	moderate
February Weather	-1°C (30°F)	27 mm (1.1 inches)	77%	moderate
March Weather	7°C (45°F)	86 mm (3.4 inches)	70%	high
April Weather	12°C (53°F)	60 mm (2.4 inches)	73%	very high
May Weather	18°C (65°F)	201 mm (7.9 inches)	82%	very high
June Weather	25°C (78°F)	94 mm (3.7 inches)	82%	extreme
July Weather	27°C (81°F)	89 mm (3.5 inches)	81%	extreme
August Weather	25°C (77°F)	95 mm (3.7 inches)	78%	very high
September Weather	22°C (72°F)	67 mm (2.7 inches)	71%	very high
October Weather	13°C (55°F)	121 mm (4.8 inches)	71%	high
November Weather	6°C (43°F)	31 mm (1.2 inches)	81%	moderate
December Weather	2°C (35°F)	28 mm (1.1 inches)	84%	moderate