August Weather in Washington, United States

Last updated: June 24, 2025

In Washington, United States, the average temperature in August reaches a warm 28°C (83°F). However, temperatures can vary significantly, dipping to a cool 12°C (55°F) and soaring to a scorching 41°C (106°F). Rainfall is minimal, with an average of just 10 mm (0.4 in) over 2 days. The average humidity lingers at a comfortable 31%, making for a pleasant experience overall.

August Temperature in Washington

In August in Washington, the average temperature is 28°C (83°F). Maximums can reach 41°C (106°F), while minimums can drop to as low as 12°C (55°F). Travelers should be prepared for warm, sometimes scorching daytime temperatures, as well as 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 28°C (83°F), with highs reaching up to 41°C (106°F) and lows dropping to around 12°C (55°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 10 mm (0.4 in) over a period of 2 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 10 mm (0.4 inches) of precipitation spread over approximately 2 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 31%. With an average temperature of 28°C (83°F), this humidity feels like a warm, inviting embrace that's not overly oppressive, making it pleasant for exploring outdoor attractions and enjoying leisurely strolls in comfortable weather.

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 31%, 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 11, which corresponds to an extreme Exposure Category. With a time to burn of just 10 minutes, it's essential to take precautions. For more details, 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 11, which falls under the extreme 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	3°C (38°F)	48 mm (1.9 inches)	80%	moderate
February Weather	5°C (41°F)	42 mm (1.7 inches)	82%	high
March Weather	9°C (49°F)	48 mm (1.9 inches)	72%	very high
April Weather	15°C (59°F)	12 mm (0.5 inches)	62%	very high
May Weather	19°C (67°F)	16 mm (0.6 inches)	45%	extreme
June Weather	27°C (80°F)	1 mm (0.0 inches)	34%	extreme
July Weather	29°C (85°F)	9 mm (0.3 inches)	30%	extreme
August Weather	28°C (83°F)	10 mm (0.4 inches)	31%	extreme
September Weather	24°C (75°F)	5 mm (0.2 inches)	47%	very high
October Weather	15°C (59°F)	13 mm (0.5 inches)	62%	high
November Weather	9°C (49°F)	29 mm (1.1 inches)	77%	moderate
December Weather	4°C (39°F)	35 mm (1.4 inches)	80%	moderate