SmogRank / World / United States / California / August 2024

Most polluted cities in California, United States, August 2024

108 cities in California, United States ranked by their average PM2.5 over the 31 days. Worst: Fontana at 14.8 µg/m³, #160 of 1,962 cities in the world. Cleanest: Sebastopol 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.

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

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SmogRank, most polluted cities in California, United States, PM2.5, August 2024, smogrank.com/us/region/california/history/2024-08 (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.