SmogRank / World / United States / California / December 2023

Most polluted cities in California, United States, December 2023

102 cities in California, United States ranked by their average PM2.5 over the 31 days. Worst: Bakersfield at 25.5 µg/m³, #92 of 2,197 cities in the world. Cleanest: Solvang at 2.7. A city needs measurements on 70% of the days to be ranked.

Ranked by unhealthy days: the share of each city's measured days with a daily mean over 35.4 µg/m³ (US AQI 101+), Unhealthy for Sensitive Groups or worse on the US EPA's scale. Ties go to the higher average.

← Hanford 23% 20%0
Every city in California, United States ranked for December 2023, one column each, ranked by unhealthy days: height is the share of its measured days that were unhealthy, colour its average. Point at it to read a city; tap to open it.
  1. 1Hanford
    23%
  2. 2Fresno
    23%
  3. 3Bakersfield
    20%
  4. 4Visalia
    17%
  5. 5Stockton
    13%
  6. 6Modesto
    10%
  7. 7Turlock
    7%
  8. 8Manteca
    7%
  9. 9Corcoran
    4%
  10. 10Merced
    3%
  11. 11Madera
    3%
  12. 12Hawthornelow-cost sensors
    3%
  13. 13Carsonlow-cost sensors
    3%
  14. 14Compton
    3%
  15. 15Jurupa Valley
    3%
  16. 16Riverside
    3%
  17. 17Redding
    3%
  18. 18Imperial Beach
    0%
  19. 19Clovis
    0%
  20. 20Arden-Arcade
    0%
  21. 21Anaheim
    0%
  22. 22Porterville
    0%
  23. 23Los Angeles
    0%
  24. 24Big Bear City
    0%
  25. 24Yuba City
    0%
  26. 26Fontana
    0%
  27. 26Rio Vista
    0%
  28. 28Burbank
    0%
  29. 28San Diego
    0%
  30. 30Chico
    0%
  31. 31Yreka
    0%
  32. 32Torrancelow-cost sensors
    0%
  33. 33Long Beach
    0%
  34. 34Sacramento
    0%
  35. 35Inglewoodlow-cost sensors
    0%
  36. 35Redwood City
    0%
  37. 37El Cajon
    0%
  38. 37San Jose
    0%
  39. 39Chula Vista
    0%
  40. 40Huron
    0%
  41. 41Richmond
    0%
  42. 42Oakland
    0%
  43. 42Woodland
    0%
  44. 44Lomitalow-cost sensors
    0%
  45. 45Victorville
    0%
  46. 46Banning
    0%
  47. 46Roseville
    0%
  48. 48Livermore
    0%
  49. 48Santa Monicalow-cost sensors
    0%
  50. 50Oceanside
    0%
  51. 51Ukiah
    0%
  52. 52Pleasanton
    0%
  53. 53Brawley
    0%
  54. 53Lincoln
    0%
  55. 55North Auburn
    0%
  56. 56Agouralow-cost sensors
    0%
  57. 56El Centro
    0%
  58. 56Folsom
    0%
  59. 56Rancho Murieta
    0%
  60. 56San Francisco
    0%
  61. 56Tracy
    0%
  62. 62Crestline
    0%
  63. 62Galt
    0%
  64. 64Colusa
    0%
  65. 64Concord
    0%
  66. 66La Crescenta-Montroselow-cost sensors
    0%
  67. 67San Leandro
    0%
  68. 68Poway
    0%
  69. 68Santa Clarita
    0%
  70. 68Willows
    0%
  71. 71Ben Lomond
    0%
  72. 71Crescent City
    0%
  73. 73Davis
    0%
  74. 73Lake Elsinore
    0%
  75. 75Sebastopol
    0%
  76. 75Vacaville
    0%
  77. 75Red Bluff
    0%
  78. 78Glendora
    0%
  79. 79Santa Barbara
    0%
  80. 80Simi Valley
    0%
  81. 81Alta Sierra
    0%
  82. 81Atascadero
    0%
  83. 81Thousand Oaks
    0%
  84. 84Salinas
    0%
  85. 85Oceano
    0%
  86. 86San Rafael
    0%
  87. 87Orcutt
    0%
  88. 87South Lake Tahoe
    0%
  89. 89Gilroy
    0%
  90. 89Paradise
    0%
  91. 91Alpine
    0%
  92. 91Grass Valley
    0%
  93. 93Santa Cruz
    0%
  94. 94Ojai
    0%
  95. 95Hollister
    0%
  96. 96Carpinteria
    0%
  97. 96King City
    0%
  98. 98Fillmore
    0%
  99. 98Guadalupe
    0%
  100. 98Lompoc
    0%
  101. 98San Luis Obispo
    0%
  102. 102Solvang
    0%

Low-cost sensors: consumer units, counted only in cities with no government-grade monitor; they read close to reference monitors on the whole, but 15 to 25% high in humid air. How we use them.

Good0–50
Moderate51–100
Sensitive groups101–150
Unhealthy151–200
Very unhealthy201–300
Hazardous301+

The US EPA's Air Quality Index for PM2.5 (2024 breakpoints). Show values as: µg/m³ · US AQI · India AQI · China AQI · European AQI · UK DAQI · Canada AQHI+. About the scales

All cities in the world, December 2023 · All cities in United States, December 2023 · California now

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SmogRank, most polluted cities in California, United States, PM2.5, December 2023, smogrank.com/us/region/california/history/2023-12 (accessed 6 Oct 2026).

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You're welcome to reuse a single chart, image or figure with this citation and a link. Terms. Raw monitor readings in bulk are published by OpenAQ, under each provider's licence.