SmogRank / World / United States / California / 2025

Most polluted cities in California, United States, 2025

113 cities in California, United States ranked by their average PM2.5 over the 365 days; 101 above the WHO annual guideline (5.0 µg/m³). Worst: Imperial Beach at 13.8 µg/m³, #470 of 2,624 cities in the world. Cleanest: Ridgecrest at 3.8. 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.

← Jurupa Valley 3% 2%0
Every city in California, United States ranked for 2025, 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. 1Jurupa Valley
    3%
  2. 2Compton
    3%
  3. 3Imperial Beach
    2%
  4. 4Anaheim
    1%
  5. 5Riverside
    1%
  6. 6Calexico
    1%
  7. 7Los Angeles
    1%
  8. 8Yreka
    1%
  9. 9Long Beach
    1%
  10. 10Hawthornelow-cost sensors
    1%
  11. 11Brawley
    1%
  12. 12Corcoran
    1%
  13. 13Burbank
    1%
  14. 14Santa Monicalow-cost sensors
    1%
  15. 15Carsonlow-cost sensors
    1%
  16. 16Fillmore
    1%
  17. 17Fontana
    1%
  18. 18Bakersfield
    1%
  19. 19Inglewoodlow-cost sensors
    0%
  20. 20La Crescenta-Montroselow-cost sensors
    0%
  21. 21Temecula
    0%
  22. 22Torrancelow-cost sensors
    0%
  23. 23Palo Altolow-cost sensors
    0%
  24. 24Red Bluff
    0%
  25. 25Hanford
    0%
  26. 26Willows
    0%
  27. 27Ukiah
    0%
  28. 28Redding
    0%
  29. 29Glendora
    0%
  30. 30Fresno
    0%
  31. 31El Rio
    0%
  32. 32Visalia
    0%
  33. 33San Diego
    0%
  34. 34Porterville
    0%
  35. 35Berkeley
    0%
  36. 35Lomitalow-cost sensors
    0%
  37. 35Santa Barbara
    0%
  38. 38Madera
    0%
  39. 39Woodland
    0%
  40. 40El Cajon
    0%
  41. 41Agouralow-cost sensors
    0%
  42. 42Santa Clarita
    0%
  43. 43San Jose
    0%
  44. 43Stockton
    0%
  45. 45Clovis
    0%
  46. 45Richmond
    0%
  47. 47Victorville
    0%
  48. 48Oceanside
    0%
  49. 49Modesto
    0%
  50. 49Poway
    0%
  51. 49Turlock
    0%
  52. 52Chico
    0%
  53. 52Merced
    0%
  54. 54Lake Elsinore
    0%
  55. 54Oakland
    0%
  56. 56Indio
    0%
  57. 57Roseville
    0%
  58. 57Simi Valley
    0%
  59. 59Manteca
    0%
  60. 59Arden-Arcade
    0%
  61. 61Guadalupe
    0%
  62. 62Lincoln
    0%
  63. 62Vallejo
    0%
  64. 64Yuba City
    0%
  65. 65Banning
    0%
  66. 65Martinez
    0%
  67. 65San Francisco
    0%
  68. 68Galt
    0%
  69. 69Folsom
    0%
  70. 69North Auburn
    0%
  71. 69Oceano
    0%
  72. 69Sacramento
    0%
  73. 69South San Franciscolow-cost sensors
    0%
  74. 69Thousand Oaks
    0%
  75. 75Colusa
    0%
  76. 75Gridley
    0%
  77. 75San Leandro
    0%
  78. 75Crescent City
    0%
  79. 79El Centro
    0%
  80. 80Alpine
    0%
  81. 80Crestline
    0%
  82. 82Alta Sierra
    0%
  83. 82Huron
    0%
  84. 82Rancho Murieta
    0%
  85. 85Lompoc
    0%
  86. 86Davis
    0%
  87. 86Tracy
    0%
  88. 88Gilroy
    0%
  89. 88Livermore
    0%
  90. 88Salinas
    0%
  91. 91Goletalow-cost sensors
    0%
  92. 91San Luis Obispo
    0%
  93. 93Pleasanton
    0%
  94. 93Vacaville
    0%
  95. 95Ojai
    0%
  96. 96Ben Lomond
    0%
  97. 96Grass Valley
    0%
  98. 96Redwood City
    0%
  99. 99Carpinteria
    0%
  100. 99King City
    0%
  101. 101Santa Cruz
    0%
  102. 102Lancaster
    0%
  103. 103Paradise
    0%
  104. 104San Rafael
    0%
  105. 105Atascadero
    0%
  106. 105Concord
    0%
  107. 105Hollister
    0%
  108. 108Sunnyvalelow-cost sensors
    0%
  109. 109Solvang
    0%
  110. 109Truckee
    0%
  111. 111Sebastopol
    0%
  112. 112Orcutt
    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

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SmogRank, most polluted cities in California, United States, PM2.5, 2025, smogrank.com/us/region/california/history/2025 (accessed 6 Oct 2026).

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