| County | Reported* | Tested | Positive | % Tested Positive |
| Alameda | 706 | 26 | - | - |
| Alpine | 3 | - | - | - |
| Amador | 110 | 4 | - | - |
| Butte | 751 | 10 | - | - |
| Calaveras | 129 | 7 | - | - |
| Colusa | 46 | - | - | - |
| Contra Costa | 2227 | 37 | - | - |
| Del Norte | 27 | - | - | - |
| El Dorado | 543 | 8 | - | - |
| Fresno | 1232 | 25 | - | - |
| Glenn | 92 | - | - | - |
| Humboldt | 78 | 1 | - | - |
| Imperial | 35 | - | - | - |
| Inyo | 35 | 2 | - | - |
| Kern | 1590 | 52 | 1 | 2% |
| Kings | 133 | 2 | - | - |
| Lake | 94 | - | - | - |
| Lassen | 23 | - | - | - |
| Los Angeles | 5535 | 54 | 1 | 2% |
| Madera | 121 | 12 | - | - |
| Marin | 219 | 14 | - | - |
| Mariposa | 18 | - | - | - |
| Mendocino | 79 | 3 | - | - |
| Merced | 207 | 6 | - | - |
| Modoc | 17 | - | - | - |
| Mono | 11 | - | - | - |
| Monterey | 272 | 6 | - | - |
| Napa | 88 | - | - | - |
| Nevada | 305 | 3 | - | - |
| Orange | 2996 | 51 | 1 | 2% |
| Placer | 724 | 7 | - | - |
| Plumas | 57 | 2 | - | - |
| Riverside | 1269 | 7 | - | - |
| Sacramento | 3106 | 53 | 1 | 2% |
| San Benito | 34 | - | - | - |
| San Bernardino | 1554 | 17 | - | - |
| San Diego | 1742 | 49 | 9 | 18% |
| San Francisco | 105 | 6 | - | - |
| San Joaquin | 1509 | 21 | - | - |
| San Luis Obispo | 180 | 12 | - | - |
| San Mateo | 389 | 21 | - | - |
| Santa Barbara | 96 | 3 | - | - |
| Santa Clara | 961 | 9 | 1 | 11% |
| Santa Cruz | 163 | 4 | - | - |
| Shasta | 406 | 1 | - | - |
| Sierra | 16 | - | - | - |
| Siskiyou | 21 | 1 | - | - |
| Solano | 542 | - | - | - |
| Sonoma | 495 | 20 | - | - |
| Stanislaus | 938 | 14 | - | - |
| Sutter | 179 | 1 | - | - |
| Tehama | 137 | - | - | - |
| Trinity | 14 | - | - | - |
| Tulare | 754 | 11 | - | - |
| Tuolumne | 92 | 1 | - | - |
| Ventura | 553 | 15 | - | - |
| Yolo | 534 | 6 | - | - |
| Yuba | 103 | 1 | - | - |
| State Totals | 34395 | 605 | 14 | 2% |
* 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