Los Angeles County has the highest COVID-19 infection rates in California; see where every other region lands

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. Early research suggests this strain may cause less severe illness than Delta and the original virus, however, health officials have warned an Omicron-driven surge could still increase hospitalization and death rates—especially in areas with less vaccinated populations.

The United States as of Jan. 4 reached 828,344 COVID-19-related deaths and nearly 56.5 million COVID-19 cases, according to Johns Hopkins University. Currently, 62% of the population is fully vaccinated, and 33.4% 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, with Los Angeles County landing at the top. Counties are ranked by the highest infection rate per 100,000 residents within the week leading up to Jan. 3, 2021. 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. Colusa County

• New cases per 100k in the past week: 102 (22 new cases, +450% change from previous week)
• Cumulative cases per 100k: 15,668 (3,376 total cases)
  -13.0% more cases per 100k residents than California
• Deaths per 100k in the past week: 0 (0 new deaths, 0% change from previous week)
• Cumulative deaths per 100k: 97 (21 total deaths)
  – 49.5% less deaths per 100k residents than California

49. Shasta County

• New cases per 100k in the past week: 126 (227 new cases, +161% change from previous week)
• Cumulative cases per 100k: 15,011 (27,032 total cases)
  – 8.3% more cases per 100k residents than California
• Deaths per 100k in the past week: 6 (10 new deaths, +100% change from previous week)
• Cumulative deaths per 100k: 273 (491 total deaths)
  – 42.2% more deaths per 100k residents than California

48. Mendocino County

• New cases per 100k in the past week: 128 (111 new cases, +88% change from previous week)
• Cumulative cases per 100k: 10,514 (9,121 total cases)
  -24.2% less cases per 100k residents than California
• Deaths per 100k in the past week: 0 (0 new deaths, -100% change from previous week)
• Cumulative deaths per 100k: 121 (105 total deaths)
  – 37.0% less deaths per 100k residents than California

47. Sierra County

• New cases per 100k in the past week: 133 (4 new cases, +300% change from previous week)
• Cumulative cases per 100k: 7,621 (229 total cases)
  -45.0% less cases per 100k residents than California
• Deaths per 100k in the past week: 0 (0 new deaths, 0% change from previous week)
• Cumulative deaths per 100k: 0 (0 total deaths)
  -100.0% less deaths per 100k residents than California

46. Tehama County

• New cases per 100k in the past week: 134 (87 new cases, +278% change from previous week)
• Cumulative cases per 100k: 16,210 (10,550 total cases)
  -16.9% more cases per 100k residents than California
• Deaths per 100k in the past week: 5 (3 new deaths, 0% change from previous week)
• Cumulative deaths per 100k: 214 (139 total deaths)
  – 11.5% more deaths per 100k residents than California

45. Amador County

• New cases per 100k in the past week: 136 (54 new cases, +86% change from previous week)
• Cumulative cases per 100k: 15,073 (5,992 total cases)
  -8.7% more cases per 100k residents than California
• Deaths per 100k in the past week: 0 (0 new deaths, -100% change from previous week)
• Cumulative deaths per 100k: 176 (70 total deaths)
  – 8.3% less deaths per 100k residents than California

44. Nevada County

• New cases per 100k in the past week: 148 (148 new cases, +54% change from previous week)
• Cumulative cases per 100k: 10,696 (10,670 total cases)
  -22.8% less cases per 100k residents than California
• Deaths per 100k in the past week: 0 (0 new deaths, -100% change from previous week)
• Cumulative deaths per 100k: 110 (110 total deaths)
  – 42.7% less deaths per 100k residents than California

43. Calaveras County

• New cases per 100k in the past week: 163 (75 new cases, +150% change from previous week)
• Cumulative cases per 100k: 10,321 (4,738 total cases)
  – 25.6% less cases per 100k residents than California
• Deaths per 100k in the past week: 4 (2 new deaths, 0% change from previous week)
• Cumulative deaths per 100k: 203 (93 total deaths)
  – 5.7% more deaths per 100k residents than California

42. Del Norte County

• New cases per 100k in the past week: 165 (46 new cases, +1,433% change from previous week)
• Cumulative cases per 100k: 14,026 (3,901 total cases)
  -1.2% more cases per 100k residents than California
• Deaths per 100k in the past week: 0 (0 new deaths, 0% change from previous week)
• Cumulative deaths per 100k: 155 (43 total deaths)
  – 19.3% less deaths per 100k residents than California

41. Madera County

• New cases per 100k in the past week: 186 (293 new cases, +193% change from previous week)
• Cumulative cases per 100k: 17,382 (27,347 total cases)
  -25.4% more cases per 100k residents than California
• Deaths per 100k in the past week: 0 (0 new deaths, -100% change from previous week)
• Cumulative deaths per 100k: 206 (324 total deaths)
  – 7.3% more deaths per 100k residents than California

40. Monterey County

• New cases per 100k in the past week: 191 (830 new cases, +305% change from previous week)
• Cumulative cases per 100k: 12,708 (55,161 total cases)
  -8.3% less cases per 100k residents than California
• Deaths per 100k in the past week: 1 (5 new deaths, +67% change from previous week)
• Cumulative deaths per 100k: 148 (643 total deaths)
  -22.9% less deaths per 100k residents than California

39. Yuba County

• New cases per 100k in the past week: 196 (154 new cases, +214% change from previous week)
• Cumulative cases per 100k: 14,331 (11,274 total cases)
  -3.4% more cases per 100k residents than California
• Deaths per 100k in the past week: 1 (1 new deaths, -50% change from previous week)
• Cumulative deaths per 100k: 126 (99 total deaths)
  -34.4% less deaths per 100k residents than California

38. Fresno County

• New cases per 100k in the past week: 204 (2,034 new cases, +282% change from previous week)
• Cumulative cases per 100k: 16,321 (163,067 total cases)
  -17.7% more cases per 100k residents than California
• Deaths per 100k in the past week: 2 (21 new deaths, -9% change from previous week)
• Cumulative deaths per 100k: 238 (2,379 total deaths)
  -24.0% more deaths per 100k residents than California

37. Stanislaus County

• New cases per 100k in the past week: 204 (1,124 new cases, -10% change from previous week)
• Cumulative cases per 100k: 17,276 (95,133 total cases)
  – 24.6% more cases per 100k residents than California
• Deaths per 100k in the past week: 2 (9 new deaths, +80% change from previous week)
• Cumulative deaths per 100k: 267 (1,473 total deaths)
  – 39.1% more deaths per 100k residents than California

36. Tulare County

• New cases per 100k in the past week: 204 (950 new cases, +253% change from previous week)
• Cumulative cases per 100k: 19,238 (89,686 total cases)
  -38.8% more cases per 100k residents than California
• Deaths per 100k in the past week: 5 (23 new deaths, +35% change from previous week)
• Cumulative deaths per 100k: 249 (1,160 total deaths)
  -29.7% more deaths per 100k residents than California

35. Kings County

• New cases per 100k in the past week: 206 (315 new cases, +116% change from previous week)
• Cumulative cases per 100k: 23,904 (36,559 total cases)
  -72.4% more cases per 100k residents than California
• Deaths per 100k in the past week: 5 (7 new deaths, +40% change from previous week)
• Cumulative deaths per 100k: 252 (386 total deaths)
  -31.3% more deaths per 100k residents than California

34. Merced County

• New cases per 100k in the past week: 210 (583 new cases, +245% change from previous week)
• Cumulative cases per 100k: 16,898 (46,923 total cases)
  -21.9% more cases per 100k residents than California
• Deaths per 100k in the past week: 1 (4 new deaths, 0% change from previous week)
• Cumulative deaths per 100k: 250 (694 total deaths)
  -30.2% more deaths per 100k residents than California

33. Butte County

• New cases per 100k in the past week: 221 (484 new cases, +612% change from previous week)
• Cumulative cases per 100k: 12,139 (26,607 total cases)
  -12.4% less cases per 100k residents than California
• Deaths per 100k in the past week: 5 (11 new deaths, +450% change from previous week)
• Cumulative deaths per 100k: 156 (341 total deaths)
  -18.8% less deaths per 100k residents than California

32. Sutter County

• New cases per 100k in the past week: 223 (216 new cases, +272% change from previous week)
• Cumulative cases per 100k: 15,649 (15,175 total cases)
  -12.9% more cases per 100k residents than California
• Deaths per 100k in the past week: 2 (2 new deaths, +100% change from previous week)
• Cumulative deaths per 100k: 199 (193 total deaths)
  -3.6% more deaths per 100k residents than California

31. Tuolumne County

• New cases per 100k in the past week: 240 (131 new cases, +138% change from previous week)
• Cumulative cases per 100k: 14,980 (8,161 total cases)
  – 8.1% more cases per 100k residents than California
• Deaths per 100k in the past week: 0 (0 new deaths, 0% change from previous week)
• Cumulative deaths per 100k: 167 (91 total deaths)
  -13.0% less deaths per 100k residents than California

30. Glenn County

• New cases per 100k in the past week: 243 (69 new cases, +360% change from previous week)
• Cumulative cases per 100k: 16,641 (4,725 total cases)
  -20.0% more cases per 100k residents than California
• Deaths per 100k in the past week: 0 (0 new deaths, 0% change from previous week)
• Cumulative deaths per 100k: 137 (39 total deaths)
  -28.6% less deaths per 100k residents than California

29. El Dorado County

• New cases per 100k in the past week: 255 (492 new cases, +300% change from previous week)
• Cumulative cases per 100k: 10,141 (19,556 total cases)
  -26.8% less cases per 100k residents than California
• Deaths per 100k in the past week: 0 (0 new deaths, -100% change from previous week)
• Cumulative deaths per 100k: 89 (172 total deaths)
  -53.6% less deaths per 100k residents than California

28. Humboldt County

• New cases per 100k in the past week: 269 (365 new cases, +272% change from previous week)
• Cumulative cases per 100k: 8,260 (11,197 total cases)
  -40.4% less cases per 100k residents than California
• Deaths per 100k in the past week: 0 (0 new deaths, -100% change from previous week)
• Cumulative deaths per 100k: 90 (122 total deaths)
  -53.1% less deaths per 100k residents than California

27. Mariposa County

• New cases per 100k in the past week: 273 (47 new cases, +161% change from previous week)
• Cumulative cases per 100k: 10,091 (1,736 total cases)
  -27.2% less cases per 100k residents than California
• Deaths per 100k in the past week: 0 (0 new deaths, 0% change from previous week)
• Cumulative deaths per 100k: 105 (18 total deaths)
  -45.3% less deaths per 100k residents than California

26. Placer County

• New cases per 100k in the past week: 279 (1,110 new cases, +234% change from previous week)
• Cumulative cases per 100k: 11,318 (45,083 total cases)
  -18.4% less cases per 100k residents than California
• Deaths per 100k in the past week: 0 (0 new deaths, -100% change from previous week)
• Cumulative deaths per 100k: 123 (489 total deaths)
  -35.9% less deaths per 100k residents than California

25. San Joaquin County

• New cases per 100k in the past week: 280 (2,131 new cases, +338% change from previous week)
• Cumulative cases per 100k: 14,793 (112,741 total cases)
  -6.7% more cases per 100k residents than California
• Deaths per 100k in the past week: 4 (30 new deaths, +114% change from previous week)
• Cumulative deaths per 100k: 250 (1,902 total deaths)
  -30.2% more deaths per 100k residents than California

24. Santa Cruz County

• New cases per 100k in the past week: 303 (829 new cases, +280% change from previous week)
• Cumulative cases per 100k: 8,841 (24,155 total cases)
  -36.2% less cases per 100k residents than California
• Deaths per 100k in the past week: 0 (0 new deaths, -100% change from previous week)
• Cumulative deaths per 100k: 83 (228 total deaths)
  -56.8% less deaths per 100k residents than California

23. Solano County

• New cases per 100k in the past week: 311 (1,393 new cases, +318% change from previous week)
• Cumulative cases per 100k: 11,259 (50,400 total cases)
  -18.8% less cases per 100k residents than California
• Deaths per 100k in the past week: 0 (2 new deaths, -75% change from previous week)
• Cumulative deaths per 100k: 85 (379 total deaths)
  -55.7% less deaths per 100k residents than California

22. Sacramento County

• New cases per 100k in the past week: 318 (4,936 new cases, +302% change from previous week)
• Cumulative cases per 100k: 11,571 (179,589 total cases)
  -16.5% less cases per 100k residents than California
• Deaths per 100k in the past week: 2 (35 new deaths, +400% change from previous week)
• Cumulative deaths per 100k: 164 (2,547 total deaths)
  -14.6% less deaths per 100k residents than California

21. Yolo County

• New cases per 100k in the past week: 336 (740 new cases, +263% change from previous week)
• Cumulative cases per 100k: 10,522 (23,200 total cases)
  -24.1% less cases per 100k residents than California
• Deaths per 100k in the past week: 0 (0 new deaths, -100% change from previous week)
• Cumulative deaths per 100k: 122 (270 total deaths)
  -36.5% less deaths per 100k residents than California

20. Sonoma County

• New cases per 100k in the past week: 343 (1,698 new cases, +304% change from previous week)
• Cumulative cases per 100k: 9,443 (46,679 total cases)
  -31.9% less cases per 100k residents than California
• Deaths per 100k in the past week: 0 (0 new deaths, -100% change from previous week)
• Cumulative deaths per 100k: 85 (418 total deaths)
  -55.7% less deaths per 100k residents than California

19. Alameda County

• New cases per 100k in the past week: 395 (6,605 new cases, +271% change from previous week)
• Cumulative cases per 100k: 8,204 (137,110 total cases)
  -40.8% less cases per 100k residents than California
• Deaths per 100k in the past week: 0 (5 new deaths, -44% change from previous week)
• Cumulative deaths per 100k: 92 (1,545 total deaths)
  -52.1% less deaths per 100k residents than California

18. San Luis Obispo County

• New cases per 100k in the past week: 397 (1,125 new cases, +315% change from previous week)
• Cumulative cases per 100k: 11,959 (33,857 total cases)
  -13.7% less cases per 100k residents than California
• Deaths per 100k in the past week: 0 (0 new deaths, 0% change from previous week)
• Cumulative deaths per 100k: 129 (365 total deaths)
  -32.8% less deaths per 100k residents than California

17. Contra Costa County

• New cases per 100k in the past week: 413 (4,760 new cases, +323% change from previous week)
• Cumulative cases per 100k: 9,737 (112,315 total cases)
  -29.8% less cases per 100k residents than California
• Deaths per 100k in the past week: 0 (2 new deaths, -67% change from previous week)
• Cumulative deaths per 100k: 93 (1,073 total deaths)
  -51.6% less deaths per 100k residents than California

16. Santa Barbara County

• New cases per 100k in the past week: 455 (2,030 new cases, +317% change from previous week)
• Cumulative cases per 100k: 11,512 (51,399 total cases)
  -17.0% less cases per 100k residents than California
• Deaths per 100k in the past week: 0 (1 new deaths, -80% change from previous week)
• Cumulative deaths per 100k: 127 (568 total deaths)
  -33.9% less deaths per 100k residents than California

15. Orange County

• New cases per 100k in the past week: 456 (14,466 new cases, +289% change from previous week)
• Cumulative cases per 100k: 11,291 (358,569 total cases)
  -18.6% less cases per 100k residents than California
• Deaths per 100k in the past week: 1 (26 new deaths, +100% change from previous week)
• Cumulative deaths per 100k: 185 (5,890 total deaths)
  -3.6% less deaths per 100k residents than California

14. Napa County

• New cases per 100k in the past week: 474 (653 new cases, +332% change from previous week)
• Cumulative cases per 100k: 10,599 (14,599 total cases)
  -23.5% less cases per 100k residents than California
• Deaths per 100k in the past week: 0 (0 new deaths, 0% change from previous week)
• Cumulative deaths per 100k: 78 (107 total deaths)
  -59.4% less deaths per 100k residents than California

13. San Bernardino County

• New cases per 100k in the past week: 480 (10,462 new cases, +303% change from previous week)
• Cumulative cases per 100k: 18,303 (399,021 total cases)
  -32.0% more cases per 100k residents than California
• Deaths per 100k in the past week: 0 (8 new deaths, -69% change from previous week)
• Cumulative deaths per 100k: 278 (6,051 total deaths)
  -44.8% more deaths per 100k residents than California

12. Inyo County

• New cases per 100k in the past week: 510 (92 new cases, +300% change from previous week)
• Cumulative cases per 100k: 15,333 (2,766 total cases)
  -10.6% more cases per 100k residents than California
• Deaths per 100k in the past week: 11 (2 new deaths, 0% change from previous week)
• Cumulative deaths per 100k: 272 (49 total deaths)
  -41.7% more deaths per 100k residents than California

11. Riverside County

• New cases per 100k in the past week: 516 (12,738 new cases, +287% change from previous week)
• Cumulative cases per 100k: 16,799 (415,024 total cases)
  -21.2% more cases per 100k residents than California
• Deaths per 100k in the past week: 1 (31 new deaths, 0% change from previous week)
• Cumulative deaths per 100k: 223 (5,501 total deaths)
  -16.1% more deaths per 100k residents than California

10. San Mateo County

• New cases per 100k in the past week: 525 (4,023 new cases, +376% change from previous week)
• Cumulative cases per 100k: 8,228 (63,074 total cases)
  -40.6% less cases per 100k residents than California
• Deaths per 100k in the past week: 0 (1 new deaths, 0% change from previous week)
• Cumulative deaths per 100k: 83 (636 total deaths)
  -56.8% less deaths per 100k residents than California

9. San Benito County

• New cases per 100k in the past week: 533 (335 new cases, +408% change from previous week)
• Cumulative cases per 100k: 13,575 (8,526 total cases)
  -2.1% less cases per 100k residents than California
• Deaths per 100k in the past week: 2 (1 new deaths, 0% change from previous week)
• Cumulative deaths per 100k: 132 (83 total deaths)
  -31.3% less deaths per 100k residents than California

8. Imperial County

• New cases per 100k in the past week: 539 (977 new cases, +130% change from previous week)
• Cumulative cases per 100k: 23,219 (42,076 total cases)
  -67.5% more cases per 100k residents than California
• Deaths per 100k in the past week: 0 (0 new deaths, -100% change from previous week)
• Cumulative deaths per 100k: 441 (800 total deaths)
  -129.7% more deaths per 100k residents than California

7. Ventura County

• New cases per 100k in the past week: 552 (4,670 new cases, +246% change from previous week)
• Cumulative cases per 100k: 13,342 (112,871 total cases)
  – 3.8% less cases per 100k residents than California
• Deaths per 100k in the past week: 1 (5 new deaths, 0% change from previous week)
• Cumulative deaths per 100k: 143 (1,211 total deaths)
  – 25.5% less deaths per 100k residents than California

6. Marin County

• New cases per 100k in the past week: 589 (1,525 new cases, +297% change from previous week)
• Cumulative cases per 100k: 8,195 (21,211 total cases)
  -40.9% less cases per 100k residents than California
• Deaths per 100k in the past week: 0 (0 new deaths, 0% change from previous week)
• Cumulative deaths per 100k: 96 (249 total deaths)
  -50.0% less deaths per 100k residents than California

5. San Diego County, CA

• New cases per 100k in the past week: 630 (21,043 new cases, +114% change from previous week)
• Cumulative cases per 100k: 13,510 (451,019 total cases)
  -2.5% less cases per 100k residents than California
• Deaths per 100k in the past week: 1 (27 new deaths, -37% change from previous week)
• Cumulative deaths per 100k: 134 (4,469 total deaths)
  -30.2% less deaths per 100k residents than California

4. Mono County

• New cases per 100k in the past week: 706 (102 new cases, +219% change from previous week)
• Cumulative cases per 100k: 14,691 (2,122 total cases)
  -6.0% more cases per 100k residents than California
• Deaths per 100k in the past week: 0 (0 new deaths, 0% change from previous week)
• Cumulative deaths per 100k: 28 (4 total deaths)
  -85.4% less deaths per 100k residents than California

3. Santa Clara County

• New cases per 100k in the past week: 725 (13,984 new cases, +665% change from previous week)
• Cumulative cases per 100k: 8,959 (172,711 total cases)
  -35.4% less cases per 100k residents than California
• Deaths per 100k in the past week: 0 (8 new deaths, -47% change from previous week)
• Cumulative deaths per 100k: 102 (1,969 total deaths)
  -46.9% less deaths per 100k residents than California

2. San Francisco County

• New cases per 100k in the past week: 750 (6,609 new cases, +246% change from previous week)
• Cumulative cases per 100k: 7,705 (67,923 total cases)
  -44.4% less cases per 100k residents than California
• Deaths per 100k in the past week: 0 (0 new deaths, -100% change from previous week)
• Cumulative deaths per 100k: 77 (682 total deaths)
  -59.9% less deaths per 100k residents than California

1. Los Angeles County

• New cases per 100k in the past week: 1,248 (125,259 new cases, +140% change from previous week)
• Cumulative cases per 100k: 17,345 (1,741,292 total cases)
  -25.1% more cases per 100k residents than California
• Deaths per 100k in the past week: 1 (94 new deaths, -10% change from previous week)
• Cumulative deaths per 100k: 275 (27,640 total deaths)
  -43.2% more deaths per 100k residents than California