Total Positive Counties: 51
| County | Human Cases | Horses | Dead Birds | Mosquito Samples | Sentinel Chickens |
| State Totals | 380 | 28 | 1396 | 1007 | 510 |
| Alameda | - | - | 19 | 1 | - |
| Alpine | - | - | - | - | - |
| Amador | - | - | 1 | 1 | - |
| Butte | 16 | - | 27 | 5 | 32 |
| Calaveras | - | - | 3 | - | - |
| Colusa | 2 | - | 4 | 1 | 2 |
| Contra Costa | 3 | - | 28 | 28 | 5 |
| Del Norte | - | - | - | - | - |
| El Dorado | - | - | 7 | - | - |
| Fresno | 17 | 1 | 114 | 61 | 46 |
| Glenn | 7 | - | 36 | 1 | 8 |
| Humboldt | - | - | 2 | - | - |
| Imperial | 3 | - | - | 4 | 17 |
| Inyo | - | - | 1 | - | - |
| Kern | 140 | 4 | 124 | 206 | 82 |
| Kings | 7 | 2 | 9 | 30 | 22 |
| Lake | - | - | 3 | 8 | 2 |
| Lassen | - | - | 2 | - | - |
| Los Angeles | 36 | - | 165 | 92 | 27 |
| Madera | 2 | - | 6 | 8 | 4 |
| Marin | - | - | 4 | - | - |
| Mariposa | - | - | - | - | - |
| Mendocino | 2 | - | 3 | - | - |
| Merced | 4 | - | 34 | 2 | 11 |
| Modoc | - | - | 1 | - | - |
| Mono | - | - | - | - | - |
| Monterey | - | - | - | - | - |
| Napa | 1 | - | 2 | - | - |
| Nevada | - | - | 5 | - | - |
| Orange | 9 | - | 43 | 27 | - |
| Placer | 4 | 1 | 16 | 25 | 13 |
| Plumas | - | - | 1 | - | - |
| Riverside | 17 | - | 6 | 30 | 44 |
| Sacramento | 25 | 2 | 142 | 135 | 19 |
| San Benito | - | - | - | - | - |
| San Bernardino | 4 | - | 26 | 6 | 35 |
| San Diego | 15 | 4 | 108 | 6 | 1 |
| San Francisco | - | - | 1 | - | - |
| San Joaquin | 10 | 1 | 46 | 154 | 24 |
| San Luis Obispo | - | 1 | 9 | - | - |
| San Mateo | - | - | 2 | - | - |
| Santa Barbara | - | - | 1 | - | - |
| Santa Clara | 4 | - | 83 | 10 | - |
| Santa Cruz | - | - | 6 | - | - |
| Shasta | 9 | 3 | 48 | 17 | 7 |
| Sierra | - | - | - | - | - |
| Siskiyou | - | 2 | 4 | - | - |
| Solano | 1 | 1 | 3 | - | 7 |
| Sonoma | 1 | 2 | 19 | 1 | - |
| Stanislaus | 21 | - | 130 | 88 | 35 |
| Sutter | 3 | - | 1 | 23 | 17 |
| Tehama | 4 | 2 | 20 | 2 | 8 |
| Trinity | - | - | 1 | - | - |
| Tulare | 10 | 2 | 38 | 23 | 27 |
| Tuolumne | - | - | 1 | - | - |
| Ventura | 1 | - | 15 | - | 1 |
| Yolo | 2 | - | 25 | 10 | 4 |
| Yuba | - | - | 1 | 2 | 10 |
| State Totals | 380 | 28 | 1396 | 1007 | 510 |