Average May Temperatures for Washington

Average temperatures for May at cities and other locations throughout Washington are listed below in degrees Fahrenheit and Celsius.

You can jump to a separate table for each region of the state: Olympic Peninsula & West Coast, San Juan Islands & Puget Sound, Cascade Mountains and Eastern Washington.

The tables give the normals for maximum and minimum temperatures based on weather data collected from 1991 to 2020 by the US National Centers for Environmental Information.

Olympic Peninsula & West Coast

Average May temperatures
High °F	Low °F	Place	High °C	Low °C
61	47	Aberdeen	16	8
64	43	Clearwater	18	6
65	43	Forks	18	6
64	44	Friday Harbor, San Juan Island	18	7
69	39	Grayland	20	4
59	45	Long Beach	15	7
60	48	Port Angeles	15	9

San Juan Islands, Puget Sound & South

Average daily temperatures in May
High °F	Low °F	Place	High °C	Low °C
66	48	Anacortes	19	9
64	47	Bellingham	18	8
66	47	Bremerton	19	8
67	44	Centralia	19	7
63	48	Everett	17	9
69	45	Longview	20	7
65	47	Mount Vernon	18	8
73	49	Oak Harbor, Whidbey Island	23	10
62	48	Olga, Orcas Island	16	9
66	43	Olympia	19	6
63	47	Port Townsend	17	8
66	49	Seattle	19	9
67	44	Shelton	19	7
67	49	Tacoma	19	10
66	44	Vancouver	19	7

Cascade Mountains

May temperatures: daily averages
High °F	Low °F	Place	High °C	Low °C
64	42	Baker Lake Dam	18	6
66	44	Baring	19	7
67	44	Darrington	19	7
68	40	Mt Adams Ranger Station	20	4
48	33	Mt Rainier Paradise Ranger Station	9	1
63	44	Mud Mountain Lake Dam	17	6
65	45	Ross Dam	18	7
53	38	Stampede Pass	12	4

Eastern Washington State

Average May temperatures
High °F	Low °F	Place	High °C	Low °C
67	41	Boundary Dam	20	5
72	46	Chelan	22	8
71	46	Coulee Dam	22	8
75	50	Kennewick	24	10
71	40	Leavenworth	22	4
74	45	Moses Lake	23	7
66	42	Pullman	19	6
67	45	Spokane	20	7
71	49	Walla Walla	22	10
62	48	Wenatchee	17	9
71	40	Winthrop	22	4
74	44	Yakima	23	6

Average Temperatures for Washington in May

Olympic Peninsula & West Coast

San Juan Islands, Puget Sound & South

Cascade Mountains

Eastern Washington State

Reference

More Washington Weather Information