SmogRank / World / United States / California / February 2024

Most polluted cities in California, United States, February 2024

101 cities in California, United States ranked by their average PM2.5 over the 29 days. Worst: Imperial Beach at 11.6 µg/m³, #504 of 2,437 cities in the world. Cleanest: South Lake Tahoe at 1.3. A city needs measurements on 70% of the days to be ranked.

OpenAQ's archive, where our readings come from, has almost none for one of these days. Cities in the United States and Europe have it from the EPA's and the European Environment Agency's own records of the same monitors; elsewhere a city's average is over its other days. Why.

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.

← Imperial Beach 0% 0.75%0
Every city in California, United States ranked for February 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. 1Imperial Beach
    0%
  2. 2Stockton
    0%
  3. 3Lake Elsinore
    0%
  4. 4Fresno
    0%
  5. 5Compton
    0%
  6. 6Los Angeles
    0%
  7. 6Jurupa Valley
    0%
  8. 8Hanford
    0%
  9. 9Calexico
    0%
  10. 9Visalia
    0%
  11. 11Big Bear City
    0%
  12. 12Anaheim
    0%
  13. 12Burbank
    0%
  14. 12Hawthornelow-cost sensors
    0%
  15. 15Carsonlow-cost sensors
    0%
  16. 15Indio
    0%
  17. 15Modesto
    0%
  18. 18Riverside
    0%
  19. 18Ukiah
    0%
  20. 20Merced
    0%
  21. 20Richmond
    0%
  22. 22Fontana
    0%
  23. 23Turlock
    0%
  24. 24Chula Vista
    0%
  25. 25Arden-Arcade
    0%
  26. 25Rio Vista
    0%
  27. 27Bakersfield
    0%
  28. 27Torrancelow-cost sensors
    0%
  29. 29San Diego
    0%
  30. 30Santa Cruz
    0%
  31. 30La Crescenta-Montroselow-cost sensors
    0%
  32. 32Corcoran
    0%
  33. 32Santa Clarita
    0%
  34. 34Banning
    0%
  35. 34Inglewoodlow-cost sensors
    0%
  36. 36El Cajon
    0%
  37. 36San Jose
    0%
  38. 38Madera
    0%
  39. 39Glendora
    0%
  40. 40Porterville
    0%
  41. 41Long Beach
    0%
  42. 42Lincoln
    0%
  43. 42Sacramento
    0%
  44. 42Santa Monicalow-cost sensors
    0%
  45. 45Crestline
    0%
  46. 45Yuba City
    0%
  47. 47Clovis
    0%
  48. 47Manteca
    0%
  49. 47Yreka
    0%
  50. 50Agouralow-cost sensors
    0%
  51. 50El Centro
    0%
  52. 50Lomitalow-cost sensors
    0%
  53. 50North Auburn
    0%
  54. 50Victorville
    0%
  55. 55Oceanside
    0%
  56. 55San Francisco
    0%
  57. 57Hollister
    0%
  58. 58Woodland
    0%
  59. 59Alta Sierra
    0%
  60. 59Gridley
    0%
  61. 61Chico
    0%
  62. 61Oakland
    0%
  63. 61Oceano
    0%
  64. 61Truckee
    0%
  65. 65Pleasanton
    0%
  66. 65Poway
    0%
  67. 65Redding
    0%
  68. 68Brawley
    0%
  69. 68Huron
    0%
  70. 70Alpine
    0%
  71. 71Paradise
    0%
  72. 71Roseville
    0%
  73. 71Red Bluff
    0%
  74. 74Colusa
    0%
  75. 75Grass Valley
    0%
  76. 75Simi Valley
    0%
  77. 77Rancho Murieta
    0%
  78. 78Vacaville
    0%
  79. 79Concord
    0%
  80. 80Galt
    0%
  81. 80Orcutt
    0%
  82. 80Thousand Oaks
    0%
  83. 83Salinas
    0%
  84. 83Santa Barbara
    0%
  85. 83Sebastopol
    0%
  86. 83Willows
    0%
  87. 87San Rafael
    0%
  88. 88Folsom
    0%
  89. 88Ojai
    0%
  90. 90Carpinteria
    0%
  91. 91Tracy
    0%
  92. 92San Luis Obispo
    0%
  93. 93Fillmore
    0%
  94. 93Davis
    0%
  95. 95Atascadero
    0%
  96. 95Guadalupe
    0%
  97. 97Gilroy
    0%
  98. 98King City
    0%
  99. 98Lancaster
    0%
  100. 100Lompoc
    0%
  101. 101South Lake Tahoe
    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, February 2024 · All cities in United States, February 2024 · California now

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SmogRank, most polluted cities in California, United States, PM2.5, February 2024, smogrank.com/us/region/california/history/2024-02 (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.