| County | Reported* | Tested | Positive | % Tested Positive |
| Alameda | 122 | 1 | 1 | 100% |
| Alpine | - | - | - | - |
| Amador | 4 | - | - | - |
| Butte | 8 | - | - | - |
| Calaveras | 2 | - | - | - |
| Colusa | 1 | - | - | - |
| Contra Costa | 117 | 6 | - | - |
| Del Norte | 2 | - | - | - |
| El Dorado | 9 | 4 | - | - |
| Fresno | 43 | 6 | 1 | 17% |
| Glenn | - | - | - | - |
| Humboldt | - | - | - | - |
| Imperial | - | - | - | - |
| Inyo | 1 | - | - | - |
| Kern | 7 | - | - | - |
| Kings | 8 | - | - | - |
| Lake | 2 | - | - | - |
| Lassen | - | - | - | - |
| Los Angeles | 323 | 11 | - | - |
| Madera | 4 | - | - | - |
| Marin | 20 | - | - | - |
| Mariposa | 1 | - | - | - |
| Mendocino | 2 | - | - | - |
| Merced | 8 | - | - | - |
| Modoc | - | - | - | - |
| Mono | - | - | - | - |
| Monterey | 37 | 1 | - | - |
| Napa | 9 | 2 | - | - |
| Nevada | 4 | 1 | - | - |
| Orange | 126 | 27 | - | - |
| Placer | 43 | 9 | - | - |
| Plumas | - | - | - | - |
| Riverside | 62 | 8 | - | - |
| Sacramento | 223 | 61 | - | - |
| San Benito | 1 | - | - | - |
| San Bernardino | 42 | 5 | - | - |
| San Diego | 162 | 29 | 1 | 3% |
| San Francisco | 33 | 1 | - | - |
| San Joaquin | 39 | 6 | - | - |
| San Luis Obispo | 66 | 2 | - | - |
| San Mateo | 165 | 42 | - | - |
| Santa Barbara | 52 | 1 | - | - |
| Santa Clara | 173 | 27 | 1 | 4% |
| Santa Cruz | 57 | - | - | - |
| Shasta | 6 | - | - | - |
| Sierra | - | - | - | - |
| Siskiyou | 1 | - | - | - |
| Solano | 23 | 4 | - | - |
| Sonoma | 27 | 3 | - | - |
| Stanislaus | 27 | 3 | - | - |
| Sutter | 9 | 1 | - | - |
| Tehama | 3 | - | - | - |
| Trinity | 1 | - | - | - |
| Tulare | 8 | 2 | - | - |
| Tuolumne | 1 | - | - | - |
| Ventura | 37 | 2 | - | - |
| Yolo | 64 | 11 | - | - |
| Yuba | 7 | 1 | - | - |
| State Totals | 2192 | 277 | 4 | 1% |
* 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