SmogRank / World / United States / California / December 2024

Most polluted cities in California, United States, December 2024

113 cities in California, United States ranked by their average PM2.5 over the 31 days. Worst: Bakersfield at 29.0 µg/m³, #102 of 2,573 cities in the world. Cleanest: Ridgecrest at 2.3. 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.

← Bakersfield 35% 30%0
Every city in California, United States ranked for December 2024, 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. 1Bakersfield
    35%
  2. 2Jurupa Valley
    29%
  3. 3Fresno
    29%
  4. 4Hanford
    26%
  5. 5Clovis
    23%
  6. 6Porterville
    23%
  7. 7Turlock
    16%
  8. 8Fontana
    16%
  9. 9Corcoran
    16%
  10. 10Riverside
    13%
  11. 11Madera
    13%
  12. 12Merced
    13%
  13. 13Imperial Beach
    11%
  14. 14Anaheim
    11%
  15. 15Compton
    10%
  16. 16Burbank
    10%
  17. 17Los Angeles
    10%
  18. 18Palo Altolow-cost sensors
    7%
  19. 19Florinlow-cost sensors
    6%
  20. 20Vallejo
    4%
  21. 21Martinez
    4%
  22. 22Carsonlow-cost sensors
    3%
  23. 23Long Beach
    3%
  24. 23Manteca
    3%
  25. 25Woodland
    3%
  26. 26Huron
    3%
  27. 27San Diego
    3%
  28. 28Oakland
    3%
  29. 29Lancaster
    3%
  30. 30Hawthornelow-cost sensors
    0%
  31. 31Inglewoodlow-cost sensors
    0%
  32. 32Torrancelow-cost sensors
    0%
  33. 33Santa Monicalow-cost sensors
    0%
  34. 33Rio Vista
    0%
  35. 35Lomitalow-cost sensors
    0%
  36. 36Berkeley
    0%
  37. 37Chula Vista
    0%
  38. 37San Jose
    0%
  39. 39Sacramento
    0%
  40. 40El Cajon
    0%
  41. 41Arden-Arcade
    0%
  42. 42Glendora
    0%
  43. 43Lake Elsinore
    0%
  44. 44Santa Barbara
    0%
  45. 45Richmond
    0%
  46. 46Agouralow-cost sensors
    0%
  47. 46Chico
    0%
  48. 48Oceanside
    0%
  49. 49Yuba City
    0%
  50. 50South San Franciscolow-cost sensors
    0%
  51. 51Galt
    0%
  52. 52La Crescenta-Montroselow-cost sensors
    0%
  53. 53Atascadero
    0%
  54. 53Tracy
    0%
  55. 55Livermore
    0%
  56. 56San Rafael
    0%
  57. 56Santa Clarita
    0%
  58. 58Rancho Murieta
    0%
  59. 58San Francisco
    0%
  60. 60Vacaville
    0%
  61. 61San Leandro
    0%
  62. 61Victorville
    0%
  63. 63Ukiah
    0%
  64. 64Concord
    0%
  65. 65Ben Lomond
    0%
  66. 65Yreka
    0%
  67. 67Pleasanton
    0%
  68. 67Watsonvillelow-cost sensors
    0%
  69. 69Poway
    0%
  70. 70Redwood City
    0%
  71. 71Folsom
    0%
  72. 71Lincoln
    0%
  73. 73Crescent City
    0%
  74. 74Davis
    0%
  75. 75Goletalow-cost sensors
    0%
  76. 75Indio
    0%
  77. 77Gilroy
    0%
  78. 77Live Oaklow-cost sensors
    0%
  79. 77Sunnyvalelow-cost sensors
    0%
  80. 80Brawley
    0%
  81. 80Prunedalelow-cost sensors
    0%
  82. 80Sebastopol
    0%
  83. 80Red Bluff
    0%
  84. 84Santa Cruz
    0%
  85. 84Redding
    0%
  86. 86Crestline
    0%
  87. 86El Centro
    0%
  88. 86South Lake Tahoe
    0%
  89. 89Seasidelow-cost sensors
    0%
  90. 89Thousand Oaks
    0%
  91. 91Simi Valley
    0%
  92. 92Guadalupe
    0%
  93. 93Hollister
    0%
  94. 94Lompoc
    0%
  95. 94Salinas
    0%
  96. 96Windsorlow-cost sensors
    0%
  97. 97El Rio
    0%
  98. 98North Auburn
    0%
  99. 99San Luis Obispo
    0%
  100. 100Banning
    0%
  101. 100Carpinteria
    0%
  102. 100Temecula
    0%
  103. 103Oceano
    0%
  104. 104King City
    0%
  105. 105Ojai
    0%
  106. 106Alpine
    0%
  107. 106Orcutt
    0%
  108. 108Grass Valley
    0%
  109. 109Fillmore
    0%
  110. 110Alta Sierra
    0%
  111. 110Truckee
    0%
  112. 112Solvang
    0%
  113. 113Ridgecrest
    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 2024 · All cities in United States, December 2024 · California now

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SmogRank, most polluted cities in California, United States, PM2.5, December 2024, smogrank.com/us/region/california/history/2024-12 (accessed 7 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.