| County | Reported* | Tested | Positive | % Tested Positive |
| Alameda | 706 | 55 | - | - |
| Alpine | 3 | - | - | - |
| Amador | 110 | 8 | - | - |
| Butte | 751 | 32 | 1 | 3% |
| Calaveras | 129 | 13 | - | - |
| Colusa | 46 | - | - | - |
| Contra Costa | 2227 | 94 | 1 | 1% |
| Del Norte | 27 | - | - | - |
| El Dorado | 543 | 25 | 1 | 4% |
| Fresno | 1232 | 69 | - | - |
| Glenn | 92 | 4 | - | - |
| Humboldt | 78 | 2 | - | - |
| Imperial | 35 | - | - | - |
| Inyo | 35 | 3 | - | - |
| Kern | 1590 | 130 | 1 | 1% |
| Kings | 133 | 6 | - | - |
| Lake | 94 | 1 | - | - |
| Lassen | 23 | - | - | - |
| Los Angeles | 5535 | 208 | 25 | 12% |
| Madera | 121 | 14 | - | - |
| Marin | 219 | 16 | - | - |
| Mariposa | 18 | 2 | - | - |
| Mendocino | 79 | 6 | - | - |
| Merced | 207 | 15 | - | - |
| Modoc | 17 | - | - | - |
| Mono | 11 | - | - | - |
| Monterey | 272 | 11 | - | - |
| Napa | 88 | - | - | - |
| Nevada | 305 | 17 | 1 | 6% |
| Orange | 2996 | 182 | 58 | 32% |
| Placer | 724 | 9 | - | - |
| Plumas | 57 | 8 | - | - |
| Riverside | 1269 | 32 | 3 | 9% |
| Sacramento | 3106 | 141 | 3 | 2% |
| San Benito | 34 | 2 | - | - |
| San Bernardino | 1554 | 58 | 5 | 9% |
| San Diego | 1742 | 116 | 42 | 36% |
| San Francisco | 105 | 7 | - | - |
| San Joaquin | 1509 | 75 | 6 | 8% |
| San Luis Obispo | 180 | 15 | - | - |
| San Mateo | 389 | 40 | 1 | 3% |
| Santa Barbara | 96 | 5 | - | - |
| Santa Clara | 961 | 41 | 4 | 10% |
| Santa Cruz | 163 | 9 | - | - |
| Shasta | 406 | 12 | 5 | 42% |
| Sierra | 16 | - | - | - |
| Siskiyou | 21 | 1 | - | - |
| Solano | 542 | 6 | - | - |
| Sonoma | 495 | 45 | - | - |
| Stanislaus | 938 | 53 | 2 | 4% |
| Sutter | 179 | 6 | 2 | 33% |
| Tehama | 137 | 8 | - | - |
| Trinity | 14 | - | - | - |
| Tulare | 754 | 87 | 22 | 25% |
| Tuolumne | 92 | 2 | - | - |
| Ventura | 553 | 35 | - | - |
| Yolo | 534 | 16 | - | - |
| Yuba | 103 | 4 | - | - |
| State Totals | 34395 | 1746 | 183 | 10% |
* 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