May Weather in Washington, United States

Last updated: June 24, 2025

In May, the average temperature in Washington, United States is a pleasant 19°C (67°F). Temperatures can vary significantly, with a minimum of 2°C (35°F) and a maximum reaching up to 36°C (97°F). Expect 16 mm (0.6 in) of precipitation over approximately 3 days, all while enjoying an average humidity level of 45%.

May Temperature in Washington

In May in Washington, the average temperature is 19°C (67°F). Maximum temperatures can reach 36°C (97°F), while minimums can drop as low as 2°C (35°F). Be prepared for warm days and cooler nights as you explore this vibrant destination.

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

The chart illustrates May 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, May typically has an average temperature of 19°C (67°F), with highs reaching up to 36°C (97°F) and lows dropping to around 2°C (35°F).

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

May Precipitation in Washington

In Washington in May, the precipitation amount is 16 mm (0.6 in), spread over a duration of 3 days.

May Precipitation Trends in Washington

The chart displays monthly precipitation patterns in Washington, with values for each month alongside May’s data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how May’s conditions compare to those of other months. In Washington, May typically receives around 16 mm (0.6 inches) of precipitation spread over approximately 3 days.

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

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Millimeters (mm) Inches (in)

May Humidity in Washington

In Washington in May, humidity is 45%. With an average temperature of 19°C (67°F), this humidity feels like a comfortable embrace, making it pleasant for traveling and exploring the beautiful surroundings without feeling overly warm or sticky.

May Average Humidity in Washington

This chart illustrates the average monthly humidity levels in Washington, with May’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In May, average humidity in Washington is approximately 45%, offering insight into how humid the weather typically is during this month.

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

May UV Index in Washington

In Washington in May, 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 May

The chart shows the monthly maximum UV Index (UVI) for Washington in May, 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 May, the maximum UV index in Washington typically reaches 11, which falls under the extreme exposure category.

Data source: Washington May 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 May 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 May’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 May’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