The vaccine deployment in December 2020 signaled a turning point in the COVID-19 pandemic. By the end of May 2021, 40% of the U.S. population was fully vaccinated. But as vaccination rates lagged over the summer, new surges of COVID-19 came, including Delta in the summer of 2021, and now the Omicron variant, which comprises the majority of cases in the U.S.

Researchers around the world have reported that Omicron is more transmissible than Delta, making breakthrough and repeat infections more likely.

The United States as of Apr. 6 reached 983,229 COVID-19-related deaths and 80.2 million COVID-19 cases, according to Johns Hopkins University. Currently, 65.6% of the population is fully vaccinated, and 45% of vaccinated people have received booster doses.

Stacker compiled a list of the counties with highest COVID-19 infection rates in California using data from the U.S. Department of Health & Human Services and vaccination data from Covid Act Now. Counties are ranked by the highest infection rate per 100,000 residents within the week leading up to Apr. 5, 2022. Cumulative cases per 100,000 served as a tiebreaker.

Keep reading to see whether your county ranks among the highest COVID-19 infection rates in your state.

#50. Glenn County, CA

– New cases per 100k in the past week: 7 (2 new cases, -91% change from previous week)
– Cumulative cases per 100k: 23,101 (6,559 total cases)
— 0.4% more cases per 100k residents than California
– Cumulative deaths per 100k: 166 (47 total deaths)
— 25.6% less deaths per 100k residents than California
– Population that is fully vaccinated: 54.8% (15,573 fully vaccinated)

#49. Lake County, CA

– New cases per 100k in the past week: 8 (5 new cases, -72% change from previous week)
– Cumulative cases per 100k: 17,973 (11,572 total cases)
— 21.9% less cases per 100k residents than California
– Cumulative deaths per 100k: 211 (136 total deaths)
— 5.4% less deaths per 100k residents than California
– Population that is fully vaccinated: 54.5% (35,120 fully vaccinated)

#48. Tehama County, CA

– New cases per 100k in the past week: 8 (5 new cases, -83% change from previous week)
– Cumulative cases per 100k: 22,512 (14,652 total cases)
— 2.2% less cases per 100k residents than California
– Cumulative deaths per 100k: 304 (198 total deaths)
— 36.3% more deaths per 100k residents than California
– Population that is fully vaccinated: 42.7% (27,759 fully vaccinated)

#47. Kern County, CA

– New cases per 100k in the past week: 8 (75 new cases, -67% change from previous week)
– Cumulative cases per 100k: 26,403 (237,682 total cases)
— 14.7% more cases per 100k residents than California
– Cumulative deaths per 100k: 247 (2,224 total deaths)
— 10.8% more deaths per 100k residents than California
– Population that is fully vaccinated: 53.1% (478,250 fully vaccinated)

#46. Inyo County, CA

– New cases per 100k in the past week: 11 (2 new cases, -50% change from previous week)
– Cumulative cases per 100k: 25,206 (4,547 total cases)
— 9.5% more cases per 100k residents than California
– Cumulative deaths per 100k: 310 (56 total deaths)
— 39.0% more deaths per 100k residents than California
– Population that is fully vaccinated: 61.7% (11,135 fully vaccinated)

#45. Nevada County, CA

– New cases per 100k in the past week: 12 (12 new cases, +100% change from previous week)
– Cumulative cases per 100k: 17,217 (17,175 total cases)
— 25.2% less cases per 100k residents than California
– Cumulative deaths per 100k: 123 (123 total deaths)
— 44.8% less deaths per 100k residents than California
– Population that is fully vaccinated: 62.6% (62,463 fully vaccinated)

#44. Imperial County, CA

– New cases per 100k in the past week: 12 (22 new cases, -91% change from previous week)
– Cumulative cases per 100k: 36,638 (66,394 total cases)
— 59.2% more cases per 100k residents than California
– Cumulative deaths per 100k: 501 (908 total deaths)
— 124.7% more deaths per 100k residents than California
– Population that is fully vaccinated: 93.4% (169,217 fully vaccinated)

#43. Mono County, CA

– New cases per 100k in the past week: 14 (2 new cases, -67% change from previous week)
– Cumulative cases per 100k: 21,386 (3,089 total cases)
— 7.1% less cases per 100k residents than California
– Cumulative deaths per 100k: 42 (6 total deaths)
— 81.2% less deaths per 100k residents than California
– Population that is fully vaccinated: 61.8% (8,926 fully vaccinated)

#42. Riverside County, CA

– New cases per 100k in the past week: 14 (349 new cases, -45% change from previous week)
– Cumulative cases per 100k: 25,043 (618,706 total cases)
— 8.8% more cases per 100k residents than California
– Cumulative deaths per 100k: 260 (6,418 total deaths)
— 16.6% more deaths per 100k residents than California
– Population that is fully vaccinated: 57.7% (1,426,336 fully vaccinated)

#41. San Joaquin County, CA

– New cases per 100k in the past week: 16 (119 new cases, -67% change from previous week)
– Cumulative cases per 100k: 23,030 (175,524 total cases)
— 0.0% more cases per 100k residents than California
– Cumulative deaths per 100k: 289 (2,202 total deaths)
— 29.6% more deaths per 100k residents than California
– Population that is fully vaccinated: 61.0% (464,879 fully vaccinated)

#40. Mariposa County, CA

– New cases per 100k in the past week: 17 (3 new cases, -67% change from previous week)
– Cumulative cases per 100k: 15,073 (2,593 total cases)
— 34.5% less cases per 100k residents than California
– Cumulative deaths per 100k: 169 (29 total deaths)
— 24.2% less deaths per 100k residents than California
– Population that is fully vaccinated: 44.1% (7,583 fully vaccinated)

#39. Calaveras County, CA

– New cases per 100k in the past week: 17 (8 new cases, -47% change from previous week)
– Cumulative cases per 100k: 16,578 (7,610 total cases)
— 28.0% less cases per 100k residents than California
– Cumulative deaths per 100k: 259 (119 total deaths)
— 16.1% more deaths per 100k residents than California
– Population that is fully vaccinated: 53.0% (24,335 fully vaccinated)

#38. Orange County, CA

– New cases per 100k in the past week: 17 (530 new cases, -36% change from previous week)
– Cumulative cases per 100k: 18,497 (587,408 total cases)
— 19.6% less cases per 100k residents than California
– Cumulative deaths per 100k: 217 (6,880 total deaths)
— 2.7% less deaths per 100k residents than California
– Population that is fully vaccinated: 72.0% (2,287,242 fully vaccinated)

#37. Del Norte County, CA

– New cases per 100k in the past week: 18 (5 new cases, 0% change from previous week)
– Cumulative cases per 100k: 21,606 (6,009 total cases)
— 6.1% less cases per 100k residents than California
– Cumulative deaths per 100k: 180 (50 total deaths)
— 19.3% less deaths per 100k residents than California
– Population that is fully vaccinated: 47.2% (13,120 fully vaccinated)

#36. Amador County, CA

– New cases per 100k in the past week: 18 (7 new cases, -65% change from previous week)
– Cumulative cases per 100k: 22,970 (9,131 total cases)
— 0.2% less cases per 100k residents than California
– Cumulative deaths per 100k: 216 (86 total deaths)
— 3.1% less deaths per 100k residents than California
– Population that is fully vaccinated: 52.2% (20,742 fully vaccinated)

#35. Humboldt County, CA

– New cases per 100k in the past week: 18 (25 new cases, 0% change from previous week)
– Cumulative cases per 100k: 14,662 (19,875 total cases)
— 36.3% less cases per 100k residents than California
– Cumulative deaths per 100k: 103 (140 total deaths)
— 53.8% less deaths per 100k residents than California
– Population that is fully vaccinated: 65.6% (88,863 fully vaccinated)

#34. Placer County, CA

– New cases per 100k in the past week: 18 (70 new cases, -59% change from previous week)
– Cumulative cases per 100k: 17,598 (70,097 total cases)
— 23.6% less cases per 100k residents than California
– Cumulative deaths per 100k: 154 (614 total deaths)
— 30.9% less deaths per 100k residents than California
– Population that is fully vaccinated: 66.5% (265,079 fully vaccinated)

#33. Mendocino County, CA

– New cases per 100k in the past week: 20 (17 new cases, -54% change from previous week)
– Cumulative cases per 100k: 18,504 (16,052 total cases)
— 19.6% less cases per 100k residents than California
– Cumulative deaths per 100k: 137 (119 total deaths)
— 38.6% less deaths per 100k residents than California
– Population that is fully vaccinated: 68.2% (59,186 fully vaccinated)

#32. El Dorado County, CA

– New cases per 100k in the past week: 20 (38 new cases, -55% change from previous week)
– Cumulative cases per 100k: 15,528 (29,944 total cases)
— 32.5% less cases per 100k residents than California
– Cumulative deaths per 100k: 104 (200 total deaths)
— 53.4% less deaths per 100k residents than California
– Population that is fully vaccinated: 60.5% (116,732 fully vaccinated)

#31. Merced County, CA

– New cases per 100k in the past week: 22 (61 new cases, -46% change from previous week)
– Cumulative cases per 100k: 25,449 (70,668 total cases)
— 10.6% more cases per 100k residents than California
– Cumulative deaths per 100k: 291 (808 total deaths)
— 30.5% more deaths per 100k residents than California
– Population that is fully vaccinated: 51.3% (142,337 fully vaccinated)

#30. Siskiyou County, CA

– New cases per 100k in the past week: 23 (10 new cases, -23% change from previous week)
– Cumulative cases per 100k: 16,525 (7,195 total cases)
— 28.2% less cases per 100k residents than California
– Cumulative deaths per 100k: 184 (80 total deaths)
— 17.5% less deaths per 100k residents than California
– Population that is fully vaccinated: 48.6% (21,171 fully vaccinated)

#29. Madera County, CA

– New cases per 100k in the past week: 24 (38 new cases, -34% change from previous week)
– Cumulative cases per 100k: 27,586 (43,400 total cases)
— 19.8% more cases per 100k residents than California
– Cumulative deaths per 100k: 225 (354 total deaths)
— 0.9% more deaths per 100k residents than California
– Population that is fully vaccinated: 54.0% (84,924 fully vaccinated)

#28. San Benito County, CA

– New cases per 100k in the past week: 25 (16 new cases, -30% change from previous week)
– Cumulative cases per 100k: 21,368 (13,421 total cases)
— 7.2% less cases per 100k residents than California
– Cumulative deaths per 100k: 156 (98 total deaths)
— 30.0% less deaths per 100k residents than California
– Population that is fully vaccinated: 71.7% (45,040 fully vaccinated)

#27. Butte County, CA

– New cases per 100k in the past week: 25 (54 new cases, -23% change from previous week)
– Cumulative cases per 100k: 18,086 (39,643 total cases)
— 21.4% less cases per 100k residents than California
– Cumulative deaths per 100k: 181 (396 total deaths)
— 18.8% less deaths per 100k residents than California
– Population that is fully vaccinated: 52.9% (115,874 fully vaccinated)

#26. Sacramento County, CA

– New cases per 100k in the past week: 26 (410 new cases, -26% change from previous week)
– Cumulative cases per 100k: 19,529 (303,102 total cases)
— 15.2% less cases per 100k residents than California
– Cumulative deaths per 100k: 190 (2,950 total deaths)
— 14.8% less deaths per 100k residents than California
– Population that is fully vaccinated: 67.0% (1,040,511 fully vaccinated)

#25. Ventura County, CA

– New cases per 100k in the past week: 27 (228 new cases, -32% change from previous week)
– Cumulative cases per 100k: 21,551 (182,326 total cases)
— 6.4% less cases per 100k residents than California
– Cumulative deaths per 100k: 173 (1,460 total deaths)
— 22.4% less deaths per 100k residents than California
– Population that is fully vaccinated: 71.6% (605,573 fully vaccinated)

#24. Napa County, CA

– New cases per 100k in the past week: 28 (39 new cases, -15% change from previous week)
– Cumulative cases per 100k: 19,402 (26,725 total cases)
— 15.7% less cases per 100k residents than California
– Cumulative deaths per 100k: 104 (143 total deaths)
— 53.4% less deaths per 100k residents than California
– Population that is fully vaccinated: 78.5% (108,111 fully vaccinated)

#23. Los Angeles County, CA

– New cases per 100k in the past week: 28 (2,860 new cases, -57% change from previous week)
– Cumulative cases per 100k: 28,160 (2,827,023 total cases)
— 22.3% more cases per 100k residents than California
– Cumulative deaths per 100k: 313 (31,410 total deaths)
— 40.4% more deaths per 100k residents than California
– Population that is fully vaccinated: 72.7% (7,300,223 fully vaccinated)

#22. San Bernardino County, CA

– New cases per 100k in the past week: 33 (713 new cases, -10% change from previous week)
– Cumulative cases per 100k: 26,881 (586,037 total cases)
— 16.8% more cases per 100k residents than California
– Cumulative deaths per 100k: 315 (6,865 total deaths)
— 41.3% more deaths per 100k residents than California
– Population that is fully vaccinated: 56.4% (1,228,738 fully vaccinated)

#21. San Luis Obispo County, CA

– New cases per 100k in the past week: 34 (95 new cases, -61% change from previous week)
– Cumulative cases per 100k: 19,883 (56,292 total cases)
— 13.6% less cases per 100k residents than California
– Cumulative deaths per 100k: 168 (475 total deaths)
— 24.7% less deaths per 100k residents than California
– Population that is fully vaccinated: 63.5% (179,893 fully vaccinated)

#20. Solano County, CA

– New cases per 100k in the past week: 37 (166 new cases, -47% change from previous week)
– Cumulative cases per 100k: 19,524 (87,396 total cases)
— 15.2% less cases per 100k residents than California
– Cumulative deaths per 100k: 100 (446 total deaths)
— 55.2% less deaths per 100k residents than California
– Population that is fully vaccinated: 66.4% (297,345 fully vaccinated)

#19. Yuba County, CA

– New cases per 100k in the past week: 38 (30 new cases, -23% change from previous week)
– Cumulative cases per 100k: 21,668 (17,046 total cases)
— 5.9% less cases per 100k residents than California
– Cumulative deaths per 100k: 153 (120 total deaths)
— 31.4% less deaths per 100k residents than California
– Population that is fully vaccinated: 48.7% (38,334 fully vaccinated)

#18. Alameda County, CA

– New cases per 100k in the past week: 38 (636 new cases, -28% change from previous week)
– Cumulative cases per 100k: 16,127 (269,530 total cases)
— 29.9% less cases per 100k residents than California
– Cumulative deaths per 100k: 108 (1,813 total deaths)
— 51.6% less deaths per 100k residents than California
– Population that is fully vaccinated: 81.1% (1,355,746 fully vaccinated)

#17. Sonoma County, CA

– New cases per 100k in the past week: 39 (195 new cases, +6% change from previous week)
– Cumulative cases per 100k: 17,348 (85,756 total cases)
— 24.6% less cases per 100k residents than California
– Cumulative deaths per 100k: 98 (485 total deaths)
— 56.1% less deaths per 100k residents than California
– Population that is fully vaccinated: 77.9% (384,927 fully vaccinated)

#16. Sutter County, CA

– New cases per 100k in the past week: 42 (41 new cases, -59% change from previous week)
– Cumulative cases per 100k: 23,372 (22,664 total cases)
— 1.5% more cases per 100k residents than California
– Cumulative deaths per 100k: 229 (222 total deaths)
— 2.7% more deaths per 100k residents than California
– Population that is fully vaccinated: 60.1% (58,279 fully vaccinated)

#15. Santa Clara County, CA

– New cases per 100k in the past week: 42 (814 new cases, -44% change from previous week)
– Cumulative cases per 100k: 16,857 (324,974 total cases)
— 26.8% less cases per 100k residents than California
– Cumulative deaths per 100k: 117 (2,258 total deaths)
— 47.5% less deaths per 100k residents than California
– Population that is fully vaccinated: 85.1% (1,640,149 fully vaccinated)

#14. Santa Barbara County, CA

– New cases per 100k in the past week: 43 (192 new cases, +482% change from previous week)
– Cumulative cases per 100k: 20,258 (90,453 total cases)
— 12.0% less cases per 100k residents than California
– Cumulative deaths per 100k: 152 (678 total deaths)
— 31.8% less deaths per 100k residents than California
– Population that is fully vaccinated: 68.6% (306,226 fully vaccinated)

#13. Contra Costa County, CA

– New cases per 100k in the past week: 43 (494 new cases, -41% change from previous week)
– Cumulative cases per 100k: 17,505 (201,921 total cases)
— 24.0% less cases per 100k residents than California
– Cumulative deaths per 100k: 112 (1,291 total deaths)
— 49.8% less deaths per 100k residents than California
– Population that is fully vaccinated: 81.8% (943,230 fully vaccinated)

#12. Kings County, CA

– New cases per 100k in the past week: 48 (73 new cases, +59% change from previous week)
– Cumulative cases per 100k: 36,023 (55,094 total cases)
— 56.5% more cases per 100k residents than California
– Cumulative deaths per 100k: 290 (443 total deaths)
— 30.0% more deaths per 100k residents than California
– Population that is fully vaccinated: 44.6% (68,215 fully vaccinated)

#11. Santa Cruz County, CA

– New cases per 100k in the past week: 51 (139 new cases, +6% change from previous week)
– Cumulative cases per 100k: 18,102 (49,458 total cases)
— 21.4% less cases per 100k residents than California
– Cumulative deaths per 100k: 95 (259 total deaths)
— 57.4% less deaths per 100k residents than California
– Population that is fully vaccinated: 74.7% (204,120 fully vaccinated)

#10. San Mateo County, CA

– New cases per 100k in the past week: 53 (406 new cases, -12% change from previous week)
– Cumulative cases per 100k: 16,668 (127,776 total cases)
— 27.6% less cases per 100k residents than California
– Cumulative deaths per 100k: 90 (693 total deaths)
— 59.6% less deaths per 100k residents than California
– Population that is fully vaccinated: 83.9% (643,532 fully vaccinated)

#9. Marin County, CA

– New cases per 100k in the past week: 54 (140 new cases, -17% change from previous week)
– Cumulative cases per 100k: 13,810 (35,743 total cases)
— 40.0% less cases per 100k residents than California
– Cumulative deaths per 100k: 111 (287 total deaths)
— 50.2% less deaths per 100k residents than California
– Population that is fully vaccinated: 86.9% (224,917 fully vaccinated)

#8. San Francisco County, CA

– New cases per 100k in the past week: 58 (514 new cases, -35% change from previous week)
– Cumulative cases per 100k: 15,142 (133,481 total cases)
— 34.2% less cases per 100k residents than California
– Cumulative deaths per 100k: 96 (843 total deaths)
— 57.0% less deaths per 100k residents than California
– Population that is fully vaccinated: 83.1% (732,202 fully vaccinated)

#7. Yolo County, CA

– New cases per 100k in the past week: 59 (131 new cases, +18% change from previous week)
– Cumulative cases per 100k: 17,933 (39,542 total cases)
— 22.1% less cases per 100k residents than California
– Cumulative deaths per 100k: 142 (313 total deaths)
— 36.3% less deaths per 100k residents than California
– Population that is fully vaccinated: 69.8% (153,990 fully vaccinated)

#6. Tulare County, CA

– New cases per 100k in the past week: 62 (290 new cases, -19% change from previous week)
– Cumulative cases per 100k: 28,565 (133,169 total cases)
— 24.1% more cases per 100k residents than California
– Cumulative deaths per 100k: 302 (1,410 total deaths)
— 35.4% more deaths per 100k residents than California
– Population that is fully vaccinated: 54.0% (251,703 fully vaccinated)

#5. San Diego County, CA

– New cases per 100k in the past week: 63 (2,096 new cases, -13% change from previous week)
– Cumulative cases per 100k: 24,078 (803,799 total cases)
— 4.6% more cases per 100k residents than California
– Cumulative deaths per 100k: 155 (5,178 total deaths)
— 30.5% less deaths per 100k residents than California
– Population that is fully vaccinated: 77.2% (2,577,749 fully vaccinated)

#4. Modoc County, CA

– New cases per 100k in the past week: 79 (7 new cases, +250% change from previous week)
– Cumulative cases per 100k: 11,232 (993 total cases)
— 51.2% less cases per 100k residents than California
– Cumulative deaths per 100k: 90 (8 total deaths)
— 59.6% less deaths per 100k residents than California
– Population that is fully vaccinated: 41.5% (3,671 fully vaccinated)

#3. Monterey County, CA

– New cases per 100k in the past week: 87 (376 new cases, +23% change from previous week)
– Cumulative cases per 100k: 21,363 (92,730 total cases)
— 7.2% less cases per 100k residents than California
– Cumulative deaths per 100k: 167 (726 total deaths)
— 25.1% less deaths per 100k residents than California
– Population that is fully vaccinated: 72.2% (313,257 fully vaccinated)

#2. Fresno County, CA

– New cases per 100k in the past week: 99 (990 new cases, +1% change from previous week)
– Cumulative cases per 100k: 25,352 (253,293 total cases)
— 10.1% more cases per 100k residents than California
– Cumulative deaths per 100k: 272 (2,722 total deaths)
— 22.0% more deaths per 100k residents than California
– Population that is fully vaccinated: 60.7% (606,112 fully vaccinated)

#1. Plumas County, CA

– New cases per 100k in the past week: 245 (46 new cases, +142% change from previous week)
– Cumulative cases per 100k: 16,818 (3,163 total cases)
— 26.9% less cases per 100k residents than California
– Cumulative deaths per 100k: 74 (14 total deaths)
— 66.8% less deaths per 100k residents than California
– Population that is fully vaccinated: 54.5% (10,257 fully vaccinated)