| County | Reported* | Tested | Positive | % Tested Positive |
| Alameda | 254 | 9 | 9 | 100% |
| Alpine | - | - | - | - |
| Amador | 9 | - | - | - |
| Butte | 18 | 4 | - | - |
| Calaveras | 6 | - | - | - |
| Colusa | 2 | - | - | - |
| Contra Costa | 177 | 15 | - | - |
| Del Norte | 2 | - | - | - |
| El Dorado | 10 | 4 | - | - |
| Fresno | 81 | 11 | 1 | 9% |
| Glenn | - | - | - | - |
| Humboldt | 7 | - | - | - |
| Imperial | - | - | - | - |
| Inyo | 1 | - | - | - |
| Kern | 16 | 3 | - | - |
| Kings | 11 | - | - | - |
| Lake | 4 | - | - | - |
| Lassen | 1 | - | - | - |
| Los Angeles | 617 | 48 | 12 | 25% |
| Madera | 15 | 2 | 2 | 100% |
| Marin | 26 | 2 | - | - |
| Mariposa | 1 | - | - | - |
| Mendocino | 2 | - | - | - |
| Merced | 11 | - | - | - |
| Modoc | 4 | - | - | - |
| Mono | 1 | - | - | - |
| Monterey | 40 | 3 | - | - |
| Napa | 14 | 2 | - | - |
| Nevada | 15 | 3 | - | - |
| Orange | 228 | 47 | - | - |
| Placer | 110 | 41 | 1 | 2% |
| Plumas | 2 | - | - | - |
| Riverside | 113 | 20 | - | - |
| Sacramento | 424 | 156 | 22 | 14% |
| San Benito | 2 | - | - | - |
| San Bernardino | 78 | 14 | 1 | 7% |
| San Diego | 279 | 91 | 12 | 13% |
| San Francisco | 44 | 5 | - | - |
| San Joaquin | 64 | 17 | - | - |
| San Luis Obispo | 78 | 5 | - | - |
| San Mateo | 267 | 64 | 1 | 2% |
| Santa Barbara | 62 | 3 | - | - |
| Santa Clara | 336 | 105 | 24 | 23% |
| Santa Cruz | 65 | 4 | - | - |
| Shasta | 11 | 2 | - | - |
| Sierra | - | - | - | - |
| Siskiyou | 1 | - | - | - |
| Solano | 29 | 4 | - | - |
| Sonoma | 58 | 5 | - | - |
| Stanislaus | 56 | 6 | - | - |
| Sutter | 14 | 1 | - | - |
| Tehama | 4 | - | - | - |
| Trinity | 1 | - | - | - |
| Tulare | 16 | 4 | - | - |
| Tuolumne | 2 | - | - | - |
| Ventura | 54 | 13 | 2 | 15% |
| Yolo | 98 | 34 | 2 | 6% |
| Yuba | 18 | 2 | - | - |
| State Totals | 3859 | 749 | 89 | 12% |
* Birds in a die-off are not included in reported totals because the deaths are not related to WNV. A die-off is defined as a group of 10 or more same species dead birds unless the species is American Crow.
Source: Vector-Borne Disease Section, California Department of Public Health