May Weather in Washington, United States

Last updated: June 24, 2025

In May, the average temperature in Washington, United States hovers around 11°C (53°F). Expect a range of 1°C (35°F) as the minimum to a comfortable 27°C (82°F) at its peak. During this period, the region receives about 92 mm (3.6 in) of precipitation spread across 11 days, contributing to an average humidity of 76%. Whether you're braving the chill or enjoying the warmth, prepare for a mix of weather experiences!

May Temperature in Washington

In May in Washington, the average temperature is 11°C (53°F), with maximums reaching up to 27°C (82°F) and minimums dipping as low as 1°C (35°F). Be prepared for a range of weather conditions while exploring the diverse outdoor experiences that Washington has to offer.

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 11°C (53°F), with highs reaching up to 27°C (82°F) and lows dropping to around 1°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 92 mm (3.6 in) spread over 11 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 92 mm (3.6 inches) of precipitation spread over approximately 11 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 76%. With an average temperature of 11°C (53°F), this humidity feels like a brisk chill that can make outdoor excursions slightly uncomfortable, as the dampness in the air clings to your skin, making layered clothing essential for any travelers venturing out.

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 76%, 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 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 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 9, which falls under the very high 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 (26°F)	97 mm (3.8 inches)	88%	low
February Weather	-3°C (27°F)	95 mm (3.7 inches)	88%	moderate
March Weather	0°C (33°F)	78 mm (3.1 inches)	85%	moderate
April Weather	6°C (43°F)	141 mm (5.6 inches)	81%	high
May Weather	11°C (53°F)	92 mm (3.6 inches)	76%	very high
June Weather	17°C (62°F)	72 mm (2.8 inches)	74%	very high
July Weather	20°C (68°F)	102 mm (4.0 inches)	74%	very high
August Weather	20°C (68°F)	81 mm (3.2 inches)	74%	very high
September Weather	17°C (62°F)	83 mm (3.2 inches)	77%	high
October Weather	11°C (52°F)	143 mm (5.6 inches)	82%	moderate
November Weather	4°C (40°F)	121 mm (4.8 inches)	85%	moderate
December Weather	-1°C (30°F)	135 mm (5.3 inches)	84%	low