| Rank |
County |
Percentage with High School Diploma |
| 1 |
Whitman County, Washington
|
95.8%
|
| 2 |
Island County, Washington
|
94.9%
|
| 3 |
Garfield County, Washington
|
94.4%
|
| 4 |
San Juan County, Washington
|
94.2%
|
| 5 |
Jefferson County, Washington
|
93.7%
|
| 6 |
Thurston County, Washington
|
93.0%
|
| 7 |
Kitsap County, Washington
|
93.0%
|
| 8 |
Spokane County, Washington
|
92.5%
|
| 9 |
King County, Washington
|
91.9%
|
| 10 |
Lincoln County, Washington
|
91.5%
|
| 11 |
Clallam County, Washington
|
91.4%
|
| 12 |
Whatcom County, Washington
|
91.4%
|
| 13 |
Wahkiakum County, Washington
|
91.3%
|
| 14 |
Snohomish County, Washington
|
91.0%
|
| 15 |
Clark County, Washington
|
90.8%
|
| 16 |
Kittitas County, Washington
|
90.7%
|
| 17 |
Stevens County, Washington
|
90.3%
|
| 18 |
Skamania County, Washington
|
90.3%
|
| 19 |
Pierce County, Washington
|
90.1%
|
| 20 |
Pend Oreille County, Washington
|
89.0%
|
| 21 |
Asotin County, Washington
|
88.7%
|
| 22 |
Benton County, Washington
|
88.2%
|
| 23 |
Skagit County, Washington
|
87.9%
|
| 24 |
Mason County, Washington
|
87.7%
|
| 25 |
Columbia County, Washington
|
87.5%
|
| 26 |
Klickitat County, Washington
|
87.3%
|
| 27 |
Walla Walla County, Washington
|
87.1%
|
| 28 |
Cowlitz County, Washington
|
86.5%
|
| 29 |
Ferry County, Washington
|
86.1%
|
| 30 |
Pacific County, Washington
|
85.9%
|
| 31 |
Lewis County, Washington
|
85.6%
|
| 32 |
Grays Harbor County, Washington
|
84.4%
|
| 33 |
Chelan County, Washington
|
82.7%
|
| 34 |
Okanogan County, Washington
|
82.5%
|
| 35 |
Douglas County, Washington
|
80.1%
|
| 36 |
Grant County, Washington
|
75.2%
|
| 37 |
Yakima County, Washington
|
71.4%
|
| 38 |
Franklin County, Washington
|
68.8%
|
| 39 |
Adams County, Washington
|
67.5%
|