| County | Reported* | Tested | Positive | % Tested Positive |
| Alameda | 67 | 8 | 5 | 63% |
| Alpine | - | - | - | - |
| Amador | - | - | - | - |
| Butte | 7 | 3 | - | - |
| Calaveras | - | - | - | - |
| Colusa | - | - | - | - |
| Contra Costa | 56 | 2 | 1 | 50% |
| Del Norte | - | - | - | - |
| El Dorado | 7 | - | - | - |
| Fresno | 23 | - | - | - |
| Glenn | 1 | - | - | - |
| Humboldt | 1 | - | - | - |
| Imperial | - | - | - | - |
| Inyo | - | - | - | - |
| Kern | 2 | - | - | - |
| Kings | 3 | - | - | - |
| Lake | 6 | 3 | - | - |
| Lassen | - | - | - | - |
| Los Angeles | 105 | 4 | - | - |
| Madera | 2 | - | - | - |
| Marin | 14 | - | - | - |
| Mariposa | - | - | - | - |
| Mendocino | 1 | - | - | - |
| Merced | 1 | - | - | - |
| Modoc | - | - | - | - |
| Mono | - | - | - | - |
| Monterey | 8 | - | - | - |
| Napa | 8 | - | - | - |
| Nevada | 4 | - | - | - |
| Orange | 32 | - | - | - |
| Placer | 21 | 1 | - | - |
| Plumas | - | - | - | - |
| Riverside | 16 | 3 | - | - |
| Sacramento | 106 | - | - | - |
| San Benito | - | - | - | - |
| San Bernardino | 14 | 5 | - | - |
| San Diego | 47 | 25 | 2 | 8% |
| San Francisco | 14 | - | - | - |
| San Joaquin | 19 | - | - | - |
| San Luis Obispo | 2 | - | - | - |
| San Mateo | 71 | 24 | 3 | 13% |
| Santa Barbara | 4 | 2 | - | - |
| Santa Clara | 81 | 18 | 3 | 17% |
| Santa Cruz | 17 | - | - | - |
| Shasta | 7 | - | - | - |
| Sierra | - | - | - | - |
| Siskiyou | - | - | - | - |
| Solano | 16 | 3 | - | - |
| Sonoma | 20 | 2 | - | - |
| Stanislaus | 19 | - | - | - |
| Sutter | 7 | - | - | - |
| Tehama | 2 | - | - | - |
| Trinity | - | - | - | - |
| Tulare | 6 | 1 | - | - |
| Tuolumne | - | - | - | - |
| Ventura | 12 | - | - | - |
| Yolo | 45 | - | - | - |
| Yuba | 3 | - | - | - |
| State Totals | 897 | 104 | 14 | 13% |
* 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