These counties have the highest COVID-19 infection rates in California

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 May 18 reached over 1 million COVID-19-related deaths and 83.4 million COVID-19 cases, according to Johns Hopkins University. Currently, 66.5% of the population is fully vaccinated, and 46.4% 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 May 17, 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.

Canva

#50. Tulare County, CA

– New cases per 100k in the past week: 43 (201 new cases, +25% change from previous week)
– Cumulative cases per 100k: 29,199 (136,125 total cases)
— 23.6% more cases per 100k residents than California
– Cumulative deaths per 100k: 315 (1,469 total deaths)
— 38.2% more deaths per 100k residents than California
– Population that is fully vaccinated: 54.7% (254,829 fully vaccinated)

CleanWater17 // Wikimedia Commons

#49. Colusa County, CA

– New cases per 100k in the past week: 46 (10 new cases, +233% change from previous week)
– Cumulative cases per 100k: 21,112 (4,549 total cases)
— 10.6% less cases per 100k residents than California
– Cumulative deaths per 100k: 97 (21 total deaths)
— 57.5% less deaths per 100k residents than California
– Population that is fully vaccinated: 60.6% (13,051 fully vaccinated)

Doug Kerr // Wikicommons

#48. Shasta County, CA

– New cases per 100k in the past week: 50 (90 new cases, +25% change from previous week)
– Cumulative cases per 100k: 20,540 (36,988 total cases)
— 13.1% less cases per 100k residents than California
– Cumulative deaths per 100k: 309 (557 total deaths)
— 35.5% more deaths per 100k residents than California
– Population that is fully vaccinated: 46.6% (83,851 fully vaccinated)

Cbl62 // Wikicommons

#47. Imperial County, CA

– New cases per 100k in the past week: 50 (91 new cases, -42% change from previous week)
– Cumulative cases per 100k: 36,815 (66,715 total cases)
— 55.8% more cases per 100k residents than California
– Cumulative deaths per 100k: 506 (917 total deaths)
— 121.9% more deaths per 100k residents than California
– Population that is fully vaccinated: 95.0% (172,699 fully vaccinated)

Bobak Ha’Eri // Wikimedia Commons

#46. Amador County, CA

– New cases per 100k in the past week: 53 (21 new cases, -16% change from previous week)
– Cumulative cases per 100k: 23,252 (9,243 total cases)
— 1.6% less cases per 100k residents than California
– Cumulative deaths per 100k: 216 (86 total deaths)
— 5.3% less deaths per 100k residents than California
– Population that is fully vaccinated: 52.8% (20,986 fully vaccinated)

Armona // Wikicommons

#45. Kings County, CA

– New cases per 100k in the past week: 58 (88 new cases, +38% change from previous week)
– Cumulative cases per 100k: 36,242 (55,429 total cases)
— 53.4% more cases per 100k residents than California
– Cumulative deaths per 100k: 292 (447 total deaths)
— 28.1% more deaths per 100k residents than California
– Population that is fully vaccinated: 45.3% (69,253 fully vaccinated)

Chmee2 // Wikimedia Commons

#44. Siskiyou County, CA

– New cases per 100k in the past week: 62 (27 new cases, +80% change from previous week)
– Cumulative cases per 100k: 16,709 (7,275 total cases)
— 29.3% less cases per 100k residents than California
– Cumulative deaths per 100k: 186 (81 total deaths)
— 18.4% less deaths per 100k residents than California
– Population that is fully vaccinated: 49.2% (21,423 fully vaccinated)

Almonroth // Wikimedia Commons

#43. Trinity County, CA

– New cases per 100k in the past week: 65 (8 new cases, +300% change from previous week)
– Cumulative cases per 100k: 12,080 (1,484 total cases)
— 48.9% less cases per 100k residents than California
– Cumulative deaths per 100k: 163 (20 total deaths)
— 28.5% less deaths per 100k residents than California
– Population that is fully vaccinated: 48.9% (6,013 fully vaccinated)

Mark Miller // Wikimedia Commons

#42. Merced County, CA

– New cases per 100k in the past week: 73 (203 new cases, +36% change from previous week)
– Cumulative cases per 100k: 25,748 (71,497 total cases)
— 9.0% more cases per 100k residents than California
– Cumulative deaths per 100k: 295 (818 total deaths)
— 29.4% more deaths per 100k residents than California
– Population that is fully vaccinated: 52.0% (144,411 fully vaccinated)

nickchapman // Wikicommons

#41. Kern County, CA

– New cases per 100k in the past week: 74 (662 new cases, +68% change from previous week)
– Cumulative cases per 100k: 26,639 (239,804 total cases)
— 12.8% more cases per 100k residents than California
– Cumulative deaths per 100k: 257 (2,314 total deaths)
— 12.7% more deaths per 100k residents than California
– Population that is fully vaccinated: 53.8% (484,248 fully vaccinated)

Canva

#40. Calaveras County, CA

– New cases per 100k in the past week: 78 (36 new cases, +33% change from previous week)
– Cumulative cases per 100k: 16,891 (7,754 total cases)
— 28.5% less cases per 100k residents than California
– Cumulative deaths per 100k: 261 (120 total deaths)
— 14.5% more deaths per 100k residents than California
– Population that is fully vaccinated: 53.7% (24,659 fully vaccinated)

Canva

#39. Butte County, CA

– New cases per 100k in the past week: 78 (171 new cases, +68% change from previous week)
– Cumulative cases per 100k: 18,332 (40,181 total cases)
— 22.4% less cases per 100k residents than California
– Cumulative deaths per 100k: 193 (424 total deaths)
— 15.4% less deaths per 100k residents than California
– Population that is fully vaccinated: 53.4% (117,049 fully vaccinated)

Public Domain

#38. Stanislaus County, CA

– New cases per 100k in the past week: 81 (445 new cases, +26% change from previous week)
– Cumulative cases per 100k: 24,742 (136,244 total cases)
— 4.7% more cases per 100k residents than California
– Cumulative deaths per 100k: 299 (1,645 total deaths)
— 31.1% more deaths per 100k residents than California
– Population that is fully vaccinated: 57.2% (314,878 fully vaccinated)

Canva

#37. San Bernardino County, CA

– New cases per 100k in the past week: 83 (1,811 new cases, +6% change from previous week)
– Cumulative cases per 100k: 27,402 (597,377 total cases)
— 16.0% more cases per 100k residents than California
– Cumulative deaths per 100k: 340 (7,423 total deaths)
— 49.1% more deaths per 100k residents than California
– Population that is fully vaccinated: 57.1% (1,244,789 fully vaccinated)

Daniel Orth // Flickr

#36. Riverside County, CA

– New cases per 100k in the past week: 85 (2,100 new cases, -4% change from previous week)
– Cumulative cases per 100k: 25,367 (626,695 total cases)
— 7.4% more cases per 100k residents than California
– Cumulative deaths per 100k: 262 (6,471 total deaths)
— 14.9% more deaths per 100k residents than California
– Population that is fully vaccinated: 59.0% (1,456,613 fully vaccinated)

Frank Schulenburg // Wikimedia Commons

#35. Nevada County, CA

– New cases per 100k in the past week: 87 (87 new cases, +5% change from previous week)
– Cumulative cases per 100k: 17,546 (17,503 total cases)
— 25.7% less cases per 100k residents than California
– Cumulative deaths per 100k: 127 (127 total deaths)
— 44.3% less deaths per 100k residents than California
– Population that is fully vaccinated: 63.4% (63,261 fully vaccinated)

DimiTalen // Wikimedia Commons

#34. El Dorado County, CA

– New cases per 100k in the past week: 89 (171 new cases, +13% change from previous week)
– Cumulative cases per 100k: 15,820 (30,508 total cases)
— 33.0% less cases per 100k residents than California
– Cumulative deaths per 100k: 110 (212 total deaths)
— 51.8% less deaths per 100k residents than California
– Population that is fully vaccinated: 61.1% (117,743 fully vaccinated)

David Jordan // Wikicommons

#33. Fresno County, CA

– New cases per 100k in the past week: 93 (934 new cases, +29% change from previous week)
– Cumulative cases per 100k: 25,784 (257,611 total cases)
— 9.1% more cases per 100k residents than California
– Cumulative deaths per 100k: 276 (2,757 total deaths)
— 21.1% more deaths per 100k residents than California
– Population that is fully vaccinated: 61.4% (612,976 fully vaccinated)

Michael Patrick // Wikimedia Commons

#32. San Benito County, CA

– New cases per 100k in the past week: 99 (62 new cases, -3% change from previous week)
– Cumulative cases per 100k: 21,711 (13,636 total cases)
— 8.1% less cases per 100k residents than California
– Cumulative deaths per 100k: 156 (98 total deaths)
— 31.6% less deaths per 100k residents than California
– Population that is fully vaccinated: 72.6% (45,592 fully vaccinated)

Kenneth Green // Wikimedia Commons

#31. Plumas County, CA

– New cases per 100k in the past week: 101 (19 new cases, -61% change from previous week)
– Cumulative cases per 100k: 17,967 (3,379 total cases)
— 23.9% less cases per 100k residents than California
– Cumulative deaths per 100k: 69 (13 total deaths)
— 69.7% less deaths per 100k residents than California
– Population that is fully vaccinated: 55.1% (10,359 fully vaccinated)

Hollywood // Wikimedia Commons

#30. Orange County, CA

– New cases per 100k in the past week: 103 (3,284 new cases, +11% change from previous week)
– Cumulative cases per 100k: 18,906 (600,384 total cases)
— 20.0% less cases per 100k residents than California
– Cumulative deaths per 100k: 221 (7,017 total deaths)
— 3.1% less deaths per 100k residents than California
– Population that is fully vaccinated: 72.8% (2,313,311 fully vaccinated)

U.S. Army Corps of Engineers Sacramento District // Wikimedia Commons

#29. Yuba County, CA

– New cases per 100k in the past week: 106 (83 new cases, +46% change from previous week)
– Cumulative cases per 100k: 21,973 (17,286 total cases)
— 7.0% less cases per 100k residents than California
– Cumulative deaths per 100k: 155 (122 total deaths)
— 32.0% less deaths per 100k residents than California
– Population that is fully vaccinated: 49.4% (38,832 fully vaccinated)

Basar // Wikicommons

#28. San Luis Obispo County, CA

– New cases per 100k in the past week: 109 (310 new cases, -4% change from previous week)
– Cumulative cases per 100k: 20,330 (57,556 total cases)
— 13.9% less cases per 100k residents than California
– Cumulative deaths per 100k: 169 (478 total deaths)
— 25.9% less deaths per 100k residents than California
– Population that is fully vaccinated: 64.4% (182,268 fully vaccinated)

Doug Olson // Wikimedia Commons

#27. Placer County, CA

– New cases per 100k in the past week: 112 (448 new cases, +36% change from previous week)
– Cumulative cases per 100k: 17,957 (71,527 total cases)
— 24.0% less cases per 100k residents than California
– Cumulative deaths per 100k: 157 (626 total deaths)
— 31.1% less deaths per 100k residents than California
– Population that is fully vaccinated: 67.2% (267,689 fully vaccinated)

Public Domain

#26. Madera County, CA

– New cases per 100k in the past week: 112 (176 new cases, +826% change from previous week)
– Cumulative cases per 100k: 27,767 (43,685 total cases)
— 17.5% more cases per 100k residents than California
– Cumulative deaths per 100k: 232 (365 total deaths)
— 1.8% more deaths per 100k residents than California
– Population that is fully vaccinated: 54.7% (85,995 fully vaccinated)

Pixabay

#25. Santa Barbara County, CA

– New cases per 100k in the past week: 113 (505 new cases, +1% change from previous week)
– Cumulative cases per 100k: 20,758 (92,683 total cases)
— 12.1% less cases per 100k residents than California
– Cumulative deaths per 100k: 155 (693 total deaths)
— 32.0% less deaths per 100k residents than California
– Population that is fully vaccinated: 69.4% (309,947 fully vaccinated)

Bobak Ha’Eri // Wikimedia Commons

#24. Tuolumne County, CA

– New cases per 100k in the past week: 123 (67 new cases, -19% change from previous week)
– Cumulative cases per 100k: 24,667 (13,438 total cases)
— 4.4% more cases per 100k residents than California
– Cumulative deaths per 100k: 334 (182 total deaths)
— 46.5% more deaths per 100k residents than California
– Population that is fully vaccinated: 52.7% (28,705 fully vaccinated)

LPS.1 // Wikicommons

#23. San Joaquin County, CA

– New cases per 100k in the past week: 126 (963 new cases, +19% change from previous week)
– Cumulative cases per 100k: 23,421 (178,501 total cases)
— 0.9% less cases per 100k residents than California
– Cumulative deaths per 100k: 293 (2,236 total deaths)
— 28.5% more deaths per 100k residents than California
– Population that is fully vaccinated: 61.8% (470,794 fully vaccinated)

Naotake Murayama // Wikicommons

#22. Monterey County, CA

– New cases per 100k in the past week: 129 (561 new cases, +4% change from previous week)
– Cumulative cases per 100k: 21,919 (95,140 total cases)
— 7.2% less cases per 100k residents than California
– Cumulative deaths per 100k: 169 (735 total deaths)
— 25.9% less deaths per 100k residents than California
– Population that is fully vaccinated: 73.1% (317,412 fully vaccinated)

clr_flickr from Rocklin, USA // Wikimedia Commons

#21. Mono County, CA

– New cases per 100k in the past week: 132 (19 new cases, +111% change from previous week)
– Cumulative cases per 100k: 21,767 (3,144 total cases)
— 7.9% less cases per 100k residents than California
– Cumulative deaths per 100k: 42 (6 total deaths)
— 81.6% less deaths per 100k residents than California
– Population that is fully vaccinated: 62.6% (9,036 fully vaccinated)

Canva

#20. Ventura County, CA

– New cases per 100k in the past week: 134 (1,134 new cases, +31% change from previous week)
– Cumulative cases per 100k: 21,993 (186,062 total cases)
— 6.9% less cases per 100k residents than California
– Cumulative deaths per 100k: 177 (1,497 total deaths)
— 22.4% less deaths per 100k residents than California
– Population that is fully vaccinated: 72.3% (611,929 fully vaccinated)

Canva

#19. Sacramento County, CA

– New cases per 100k in the past week: 135 (2,099 new cases, +30% change from previous week)
– Cumulative cases per 100k: 20,257 (314,408 total cases)
— 14.3% less cases per 100k residents than California
– Cumulative deaths per 100k: 195 (3,022 total deaths)
— 14.5% less deaths per 100k residents than California
– Population that is fully vaccinated: 67.8% (1,052,657 fully vaccinated)

Stan Shebs // Wikicommons

#18. Napa County, CA

– New cases per 100k in the past week: 140 (193 new cases, -14% change from previous week)
– Cumulative cases per 100k: 20,156 (27,764 total cases)
— 14.7% less cases per 100k residents than California
– Cumulative deaths per 100k: 104 (143 total deaths)
— 54.4% less deaths per 100k residents than California
– Population that is fully vaccinated: 79.3% (109,177 fully vaccinated)

Epolk // Wikimedia Commons

#17. Yolo County, CA

– New cases per 100k in the past week: 147 (325 new cases, +5% change from previous week)
– Cumulative cases per 100k: 18,622 (41,061 total cases)
— 21.2% less cases per 100k residents than California
– Cumulative deaths per 100k: 143 (316 total deaths)
— 37.3% less deaths per 100k residents than California
– Population that is fully vaccinated: 70.8% (156,098 fully vaccinated)

Canva

#16. Solano County, CA

– New cases per 100k in the past week: 157 (703 new cases, +11% change from previous week)
– Cumulative cases per 100k: 19,974 (89,414 total cases)
— 15.5% less cases per 100k residents than California
– Cumulative deaths per 100k: 101 (451 total deaths)
— 55.7% less deaths per 100k residents than California
– Population that is fully vaccinated: 67.5% (302,149 fully vaccinated)

Canva

#15. Del Norte County, CA

– New cases per 100k in the past week: 158 (44 new cases, -6% change from previous week)
– Cumulative cases per 100k: 22,048 (6,132 total cases)
— 6.7% less cases per 100k residents than California
– Cumulative deaths per 100k: 180 (50 total deaths)
— 21.1% less deaths per 100k residents than California
– Population that is fully vaccinated: 48.0% (13,361 fully vaccinated)

SD Dirk // Flickr

#14. San Diego County, CA

– New cases per 100k in the past week: 167 (5,587 new cases, +20% change from previous week)
– Cumulative cases per 100k: 24,699 (824,523 total cases)
— 4.5% more cases per 100k residents than California
– Cumulative deaths per 100k: 158 (5,271 total deaths)
— 30.7% less deaths per 100k residents than California
– Population that is fully vaccinated: 74.4% (2,482,307 fully vaccinated)

Binksternet // Wikimedia Commons

#13. Mendocino County, CA

– New cases per 100k in the past week: 175 (152 new cases, +62% change from previous week)
– Cumulative cases per 100k: 19,099 (16,568 total cases)
— 19.2% less cases per 100k residents than California
– Cumulative deaths per 100k: 143 (124 total deaths)
— 37.3% less deaths per 100k residents than California
– Population that is fully vaccinated: 68.9% (59,810 fully vaccinated)

EPoelzl // Wikimedia Commons

#12. Mariposa County, CA

– New cases per 100k in the past week: 180 (31 new cases, +288% change from previous week)
– Cumulative cases per 100k: 15,544 (2,674 total cases)
— 34.2% less cases per 100k residents than California
– Cumulative deaths per 100k: 174 (30 total deaths)
— 23.7% less deaths per 100k residents than California
– Population that is fully vaccinated: 45.4% (7,810 fully vaccinated)

BDS2006 // Wikimedia

#11. Los Angeles County, CA

– New cases per 100k in the past week: 185 (18,598 new cases, +18% change from previous week)
– Cumulative cases per 100k: 28,870 (2,898,333 total cases)
— 22.2% more cases per 100k residents than California
– Cumulative deaths per 100k: 316 (31,768 total deaths)
— 38.6% more deaths per 100k residents than California
– Population that is fully vaccinated: 73.5% (7,375,596 fully vaccinated)

MARELBU // Wikimedia Commons

#10. Contra Costa County, CA

– New cases per 100k in the past week: 191 (2,201 new cases, +11% change from previous week)
– Cumulative cases per 100k: 18,201 (209,958 total cases)
— 23.0% less cases per 100k residents than California
– Cumulative deaths per 100k: 113 (1,301 total deaths)
— 50.4% less deaths per 100k residents than California
– Population that is fully vaccinated: 82.5% (951,712 fully vaccinated)

Chuck Abbe // Wikimedia Commons

#9. Inyo County, CA

– New cases per 100k in the past week: 194 (35 new cases, +250% change from previous week)
– Cumulative cases per 100k: 25,700 (4,636 total cases)
— 8.8% more cases per 100k residents than California
– Cumulative deaths per 100k: 310 (56 total deaths)
— 36.0% more deaths per 100k residents than California
– Population that is fully vaccinated: 62.8% (11,327 fully vaccinated)

Uladzik Kryhin // Shutterstock

#8. Santa Clara County, CA

– New cases per 100k in the past week: 206 (3,980 new cases, -11% change from previous week)
– Cumulative cases per 100k: 17,741 (342,015 total cases)
— 24.9% less cases per 100k residents than California
– Cumulative deaths per 100k: 119 (2,297 total deaths)
— 47.8% less deaths per 100k residents than California
– Population that is fully vaccinated: 85.8% (1,653,358 fully vaccinated)

Cory Maylett // Wikimedia Commons

#7. Humboldt County, CA

– New cases per 100k in the past week: 221 (299 new cases, +16% change from previous week)
– Cumulative cases per 100k: 15,331 (20,782 total cases)
— 35.1% less cases per 100k residents than California
– Cumulative deaths per 100k: 108 (146 total deaths)
— 52.6% less deaths per 100k residents than California
– Population that is fully vaccinated: 66.5% (90,111 fully vaccinated)

Fred Hsu // Wikicommons

#6. Sonoma County, CA

– New cases per 100k in the past week: 224 (1,109 new cases, +12% change from previous week)
– Cumulative cases per 100k: 18,245 (90,191 total cases)
— 22.8% less cases per 100k residents than California
– Cumulative deaths per 100k: 99 (488 total deaths)
— 56.6% less deaths per 100k residents than California
– Population that is fully vaccinated: 78.8% (389,514 fully vaccinated)

Aaronbrick // Wikicommons

#5. Santa Cruz County, CA

– New cases per 100k in the past week: 255 (698 new cases, -16% change from previous week)
– Cumulative cases per 100k: 19,227 (52,532 total cases)
— 18.6% less cases per 100k residents than California
– Cumulative deaths per 100k: 96 (263 total deaths)
— 57.9% less deaths per 100k residents than California
– Population that is fully vaccinated: 75.6% (206,568 fully vaccinated)

Jennifer Williams // Wikimedia Commons

#4. Alameda County, CA

– New cases per 100k in the past week: 257 (4,299 new cases, +40% change from previous week)
– Cumulative cases per 100k: 16,994 (284,033 total cases)
— 28.1% less cases per 100k residents than California
– Cumulative deaths per 100k: 111 (1,857 total deaths)
— 51.3% less deaths per 100k residents than California
– Population that is fully vaccinated: 81.9% (1,368,494 fully vaccinated)

Craig Howell // Wikimedia Commons

#3. San Mateo County, CA

– New cases per 100k in the past week: 269 (2,065 new cases, +4% change from previous week)
– Cumulative cases per 100k: 17,903 (137,238 total cases)
— 24.2% less cases per 100k residents than California
– Cumulative deaths per 100k: 92 (709 total deaths)
— 59.6% less deaths per 100k residents than California
– Population that is fully vaccinated: 84.7% (649,384 fully vaccinated)

Canva

#2. San Francisco County, CA

– New cases per 100k in the past week: 280 (2,464 new cases, -5% change from previous week)
– Cumulative cases per 100k: 16,330 (143,956 total cases)
— 30.9% less cases per 100k residents than California
– Cumulative deaths per 100k: 98 (866 total deaths)
— 57.0% less deaths per 100k residents than California
– Population that is fully vaccinated: 83.8% (738,885 fully vaccinated)

Kglavin // Wikimedia Commons

#1. Marin County, CA

– New cases per 100k in the past week: 314 (813 new cases, +45% change from previous week)
– Cumulative cases per 100k: 14,946 (38,685 total cases)
— 36.7% less cases per 100k residents than California
– Cumulative deaths per 100k: 113 (293 total deaths)
— 50.4% less deaths per 100k residents than California
– Population that is fully vaccinated: 87.6% (226,847 fully vaccinated)

Leave a Comment