| County | Reported* | Tested | Positive | % Tested Positive |
| Alameda | 290 | 77 | 2 | 3% |
| Alpine | - | - | - | - |
| Amador | 6 | - | - | - |
| Butte | 32 | 11 | 2 | 18% |
| Calaveras | 4 | - | - | - |
| Colusa | 2 | - | - | - |
| Contra Costa | 392 | 37 | 4 | 11% |
| Del Norte | 1 | - | - | - |
| El Dorado | 37 | 8 | - | - |
| Fresno | 91 | 8 | - | - |
| Glenn | 4 | - | - | - |
| Humboldt | 1 | - | - | - |
| Imperial | 1 | - | - | - |
| Inyo | 1 | - | - | - |
| Kern | 27 | 4 | - | - |
| Kings | 9 | - | - | - |
| Lake | 6 | 4 | - | - |
| Lassen | - | - | - | - |
| Los Angeles | 762 | 133 | 43 | 32% |
| Madera | 6 | 2 | - | - |
| Marin | 39 | 2 | - | - |
| Mariposa | 1 | - | - | - |
| Mendocino | 5 | - | - | - |
| Merced | 35 | 2 | 1 | 50% |
| Modoc | - | - | - | - |
| Mono | - | - | - | - |
| Monterey | 13 | 7 | - | - |
| Napa | 26 | 8 | - | - |
| Nevada | 20 | 7 | 2 | 29% |
| Orange | 553 | 435 | 7 | 2% |
| Placer | 120 | 52 | 5 | 10% |
| Plumas | - | - | - | - |
| Riverside | 108 | 26 | - | - |
| Sacramento | 712 | 403 | 100 | 25% |
| San Benito | 5 | 1 | - | - |
| San Bernardino | 111 | 26 | 1 | 4% |
| San Diego | 137 | 76 | 1 | 1% |
| San Francisco | 37 | 8 | - | - |
| San Joaquin | 133 | 54 | 17 | 31% |
| San Luis Obispo | 26 | 8 | - | - |
| San Mateo | 302 | 78 | - | - |
| Santa Barbara | 36 | 10 | - | - |
| Santa Clara | 453 | 93 | 1 | 1% |
| Santa Cruz | 66 | 18 | - | - |
| Shasta | 19 | 1 | - | - |
| Sierra | - | - | - | - |
| Siskiyou | 1 | - | - | - |
| Solano | 65 | 24 | 2 | 8% |
| Sonoma | 96 | 9 | 1 | 11% |
| Stanislaus | 124 | 14 | 2 | 14% |
| Sutter | 27 | 7 | 1 | 14% |
| Tehama | 2 | - | - | - |
| Trinity | 1 | - | - | - |
| Tulare | 48 | 14 | 7 | 50% |
| Tuolumne | 2 | 1 | - | - |
| Ventura | 48 | 14 | 1 | 7% |
| Yolo | 162 | 70 | 10 | 14% |
| Yuba | 20 | 3 | - | - |
| State Totals | 5225 | 1755 | 210 | 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