SmogRank / World / United States / California / March 2026

Most polluted cities in California, United States, March 2026

124 cities in California, United States ranked by their average PM2.5 over the 31 days. Worst: South Lake Tahoe at 32.5 µg/m³, #214 of 2,947 cities in the world. Cleanest: Sunnyvale at 3.3. 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.

← South Lake Tahoe 69% 60%0
Every city in California, United States ranked for March 2026, 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. 1South Lake Tahoe
    69%
  2. 2Delanolow-cost sensors
    10%
  3. 3Tularelow-cost sensors
    3%
  4. 4Rio Vista
    0%
  5. 5Imperial Beach
    0%
  6. 6Jurupa Valley
    0%
  7. 7Porterville
    0%
  8. 8Bakersfield
    0%
  9. 8Visalia
    0%
  10. 10Whittier
    0%
  11. 11Hawthornelow-cost sensors
    0%
  12. 12Inglewoodlow-cost sensors
    0%
  13. 13Riverside
    0%
  14. 14Los Angeles
    0%
  15. 15Fontana
    0%
  16. 16Carsonlow-cost sensors
    0%
  17. 16Compton
    0%
  18. 16Santa Monicalow-cost sensors
    0%
  19. 19Calexico
    0%
  20. 20Corcoran
    0%
  21. 21Torrancelow-cost sensors
    0%
  22. 22Fresno
    0%
  23. 23Anaheim
    0%
  24. 24San Diego
    0%
  25. 25Hanford
    0%
  26. 25Long Beach
    0%
  27. 27Chula Vista
    0%
  28. 28Lomitalow-cost sensors
    0%
  29. 29Burbank
    0%
  30. 30Santa Barbara
    0%
  31. 31Oceanside
    0%
  32. 32Agouralow-cost sensors
    0%
  33. 32Oakland
    0%
  34. 34Guadalupe
    0%
  35. 35Mission Viejo
    0%
  36. 36Modesto
    0%
  37. 36San Francisco
    0%
  38. 38Merced
    0%
  39. 38Salinas
    0%
  40. 40El Cajon
    0%
  41. 41Madera
    0%
  42. 41Poway
    0%
  43. 41Stockton
    0%
  44. 44Carpinteria
    0%
  45. 45Glendora
    0%
  46. 45San Luis Obispo
    0%
  47. 47Lake Elsinore
    0%
  48. 48San Jose
    0%
  49. 49Goletalow-cost sensors
    0%
  50. 49Richmond
    0%
  51. 49Santa Clarita
    0%
  52. 49Arden-Arcade
    0%
  53. 53San Leandro
    0%
  54. 53Woodland
    0%
  55. 55Mammoth Lakes
    0%
  56. 55Manteca
    0%
  57. 57Clovis
    0%
  58. 57Simi Valley
    0%
  59. 59Turlock
    0%
  60. 60Florinlow-cost sensors
    0%
  61. 60Oceano
    0%
  62. 62Berkeley
    0%
  63. 62Sacramento
    0%
  64. 62La Crescenta-Montroselow-cost sensors
    0%
  65. 65Santa Cruz
    0%
  66. 66El Rio
    0%
  67. 67Fillmore
    0%
  68. 67Alta Sierra
    0%
  69. 67Orcutt
    0%
  70. 70Davis
    0%
  71. 70Ukiah
    0%
  72. 72North Auburn
    0%
  73. 72Yuba City
    0%
  74. 74Brawley
    0%
  75. 74El Centro
    0%
  76. 74Gridley
    0%
  77. 74Indio
    0%
  78. 74Roseville
    0%
  79. 79Rancho Murieta
    0%
  80. 80Galt
    0%
  81. 80Ojai
    0%
  82. 82Lancaster
    0%
  83. 83Livermore
    0%
  84. 83Redwood City
    0%
  85. 85Ben Lomond
    0%
  86. 85Huron
    0%
  87. 85Vallejo
    0%
  88. 88King City
    0%
  89. 88Solvang
    0%
  90. 90Banning
    0%
  91. 90Colusa
    0%
  92. 90Lincoln
    0%
  93. 90Crescent City
    0%
  94. 94Gilroy
    0%
  95. 94Temecula
    0%
  96. 96Pleasanton
    0%
  97. 96Thousand Oaks
    0%
  98. 96Tracy
    0%
  99. 99South San Franciscolow-cost sensors
    0%
  100. 100San Rafael
    0%
  101. 100Seasidelow-cost sensors
    0%
  102. 102Hollister
    0%
  103. 103Alpine
    0%
  104. 103Big Bear City
    0%
  105. 103Concord
    0%
  106. 106Crestline
    0%
  107. 107Chico
    0%
  108. 107Folsom
    0%
  109. 109Redding
    0%
  110. 110Sebastopol
    0%
  111. 111Atascadero
    0%
  112. 111Ridgecrest
    0%
  113. 111Vacaville
    0%
  114. 111Willows
    0%
  115. 111Red Bluff
    0%
  116. 116Yreka
    0%
  117. 117Windsorlow-cost sensors
    0%
  118. 118Paradise
    0%
  119. 119Truckee
    0%
  120. 120Fremontlow-cost sensors
    0%
  121. 120Lompoc
    0%
  122. 122Martinez
    0%
  123. 123Palo Altolow-cost sensors
    0%
  124. 123Sunnyvalelow-cost sensors
    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 2026 · All cities in United States, March 2026 · California now

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SmogRank, most polluted cities in California, United States, PM2.5, March 2026, smogrank.com/us/region/california/history/2026-03 (accessed 6 Oct 2026).

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