SmogRank / World / United States / California / July 2024

Most polluted cities in California, United States, July 2024

109 cities in California, United States ranked by their average PM2.5 over the 31 days. Worst: Glendora at 20.1 µg/m³, #93 of 2,519 cities in the world. Cleanest: San Luis Obispo at 2.5. 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.

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

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SmogRank, most polluted cities in California, United States, PM2.5, July 2024, smogrank.com/us/region/california/history/2024-07 (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.