SmogRank / World / United States / California / March 2025

Most polluted cities in California, United States, March 2025

118 cities in California, United States ranked by their average PM2.5 over the 31 days. Worst: Santa Monica at 12.7 µg/m³, #1,129 of 2,809 cities in the world. Cleanest: Truckee 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.

← Santa Monica 0% 0.75%0
Every city in California, United States ranked for March 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. 1Santa Monicalow-cost sensors
    0%
  2. 2Imperial Beach
    0%
  3. 3Guadalupe
    0%
  4. 4Santa Barbara
    0%
  5. 5Jurupa Valley
    0%
  6. 6Los Angeles
    0%
  7. 7San Diego
    0%
  8. 8Hawthornelow-cost sensors
    0%
  9. 9Fontana
    0%
  10. 10Burbank
    0%
  11. 11Berkeley
    0%
  12. 11Carsonlow-cost sensors
    0%
  13. 11Riverside
    0%
  14. 14Chula Vista
    0%
  15. 15Inglewoodlow-cost sensors
    0%
  16. 16Anaheim
    0%
  17. 16Long Beach
    0%
  18. 18Pasadena
    0%
  19. 19Torrancelow-cost sensors
    0%
  20. 19Woodland
    0%
  21. 21Calexico
    0%
  22. 21Compton
    0%
  23. 23Oceano
    0%
  24. 24Clovis
    0%
  25. 25Lomitalow-cost sensors
    0%
  26. 25San Jose
    0%
  27. 27El Cajon
    0%
  28. 27Oceanside
    0%
  29. 29Santa Clarita
    0%
  30. 29Stockton
    0%
  31. 31Agouralow-cost sensors
    0%
  32. 31Ukiah
    0%
  33. 33Hanford
    0%
  34. 33Lompoc
    0%
  35. 33Poway
    0%
  36. 36Martinez
    0%
  37. 37Indio
    0%
  38. 38Atascadero
    0%
  39. 38Brawley
    0%
  40. 40Livermore
    0%
  41. 40Crescent City
    0%
  42. 42Bakersfield
    0%
  43. 42Fresno
    0%
  44. 42Porterville
    0%
  45. 42La Crescenta-Montroselow-cost sensors
    0%
  46. 46Glendora
    0%
  47. 46Oakland
    0%
  48. 48Crestline
    0%
  49. 48Lake Elsinore
    0%
  50. 48Victorville
    0%
  51. 51Corcoran
    0%
  52. 51San Francisco
    0%
  53. 51Visalia
    0%
  54. 54Salinas
    0%
  55. 55Simi Valley
    0%
  56. 56El Rio
    0%
  57. 56Arden-Arcade
    0%
  58. 58Manteca
    0%
  59. 58Turlock
    0%
  60. 60Banning
    0%
  61. 60Roseville
    0%
  62. 60San Luis Obispo
    0%
  63. 63Chico
    0%
  64. 63Folsom
    0%
  65. 65Live Oaklow-cost sensors
    0%
  66. 65Sacramento
    0%
  67. 67Modesto
    0%
  68. 67Solvang
    0%
  69. 67Yuba City
    0%
  70. 67Redding
    0%
  71. 71South San Franciscolow-cost sensors
    0%
  72. 72Alpine
    0%
  73. 72Vacaville
    0%
  74. 74Galt
    0%
  75. 74Gilroy
    0%
  76. 74Lincoln
    0%
  77. 74Santa Paula
    0%
  78. 74Thousand Oaks
    0%
  79. 74Willows
    0%
  80. 80Alta Sierra
    0%
  81. 80King City
    0%
  82. 80Vallejo
    0%
  83. 83Carpinteria
    0%
  84. 83Grass Valley
    0%
  85. 83Gridley
    0%
  86. 83Sebastopol
    0%
  87. 83Tracy
    0%
  88. 88Madera
    0%
  89. 88Santa Cruz
    0%
  90. 90Pleasanton
    0%
  91. 90San Rafael
    0%
  92. 92Merced
    0%
  93. 92Redwood City
    0%
  94. 92San Leandro
    0%
  95. 95Goletalow-cost sensors
    0%
  96. 95Red Bluff
    0%
  97. 97Ben Lomond
    0%
  98. 97North Auburn
    0%
  99. 97Orcutt
    0%
  100. 97Rancho Murieta
    0%
  101. 97Temecula
    0%
  102. 97Yreka
    0%
  103. 103Davis
    0%
  104. 103El Centro
    0%
  105. 105Concord
    0%
  106. 105Lancaster
    0%
  107. 107Hollister
    0%
  108. 107Windsorlow-cost sensors
    0%
  109. 109Fillmore
    0%
  110. 109Colusa
    0%
  111. 109Florinlow-cost sensors
    0%
  112. 112Paradise
    0%
  113. 113Ojai
    0%
  114. 114Huron
    0%
  115. 114Palo Altolow-cost sensors
    0%
  116. 116Ridgecrest
    0%
  117. 116Sunnyvalelow-cost sensors
    0%
  118. 116Truckee
    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, March 2025 · All cities in United States, March 2025 · California now

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SmogRank, most polluted cities in California, United States, PM2.5, March 2025, smogrank.com/us/region/california/history/2025-03 (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.