The Diversity Index is a scale of 0 to 100 that represents the likelyhood that two persons, chosen at random from the same area, belong to different race or ethnic groups. If an area's entire population belongs to one race AND one ethnic group, then the area has zero diversity. An area's diversity index increases to 100 when the population is evenly divided into two or more race/ethnic groups.
| Name | County | Diversity Index | |
|---|---|---|---|
| 1. | City of Wapato | Yakima | 97.4 |
| 2. | Town of Harrah | Yakima | 94.9 |
| 3. | City of Toppenish | Yakima | 92.3 |
| 4. | South Wenatchee Census Designated Place | Chelan | 88.6 |
| 5. | Boulevard Park Census Designated Place | King | 87.6 |
| 6. | City of Sunnyside | Yakima | 87.4 |
| 7. | Buena Census Designated Place | Yakima | 86.6 |
| 8. | City of Warden | Grant | 85.9 |
| 9. | City of Brewster | Okanogan | 85.6 |
| 10. | City of George | Grant | 85.6 |
| 11. | City of SeaTac | King | 85.4 |
| 12. | City of Pasco | Franklin | 85.3 |
| 13. | City of Tukwila | King | 84.2 |
| 14. | White Center Census Designated Place | King | 84.0 |
| 15. | City of Union Gap | Yakima | 83.8 |
| 16. | City of Royal City | Grant | 83.8 |
| 17. | City of Othello | Adams | 83.5 |
| 18. | City of Mabton | Yakima | 83.1 |
| 19. | City of Quincy | Grant | 82.2 |
| 20. | City of Tieton | Yakima | 81.9 |
