Average Precipitation for Washington in May





The tables below give monthly averages for rainfall plus snowfall during May at cities and other locations in Washington.

Each place has a total for the amount of precipitation it usually receives this month. There is also information on the number of days with wet weather. That includes the days when precipitation amounts to 0.01 inches (0.25 millimetres) or more.

The precipitation totals are averages based on weather data collected from 1991 to 2020 for the US National Centers for Environmental Information.

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.

Olympic Peninsula & West Coast

Average monthly precipitation in May
Days Place Inches Milli­metres
14 Aberdeen 3.5 88
15 Clearwater 5.0 128
16 Forks 5.0 126
10 Friday Harbor, San Juan Island 1.1 29
15 Grayland 3.3 83
16 Long Beach 3.6 90
11 Port Angeles 1.1 27

San Juan Islands, Puget Sound & South

May averages for total precipitation
Days Place Inches Milli­metres
11 Anacortes 1.9 47
12 Bellingham 2.2 57
12 Bremerton 2.4 60
12 Centralia 2.4 62
14 Everett 2.1 54
14 Longview 3.1 79
12 Oak Harbor, Whidbey Island 1.7 43
9 Olga, Orcas Island 1.7 43
11 Olympia 2.3 57
11 Port Townsend 1.5 39
11 Seattle 1.9 48
13 Shelton 2.6 67
10 Tacoma 2.0 51
14 Vancouver 2.8 71

Cascade Mountains

Average amount of rain and snow in May
Days Place Inches Milli­metres
14 Baker Lake Dam 4.5 115
15 Baring 5.0 128
12 Ross Dam 2.1 52

Eastern Washington State

Precipitation totals for May
Days Place Inches Milli­metres
13 Boundary Dam 2.6 66
6 Chelan 1.1 27
8 Coulee Dam 1.1 28
6 Kennewick 0.8 21
7 Leavenworth 1.4 36
6 Moses Lake 0.7 18
10 Pullman 1.8 46
10 Spokane 1.6 39
10 Walla Walla 2.1 53
6 Wenatchee 0.8 19
8 Winthrop 1.1 29
6 Yakima 0.7 19
Reference

NOAA National Centers for Environmental Information (NCEI). Climate Normals.

Washington Precipitation
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