SmogRank / Countries / United States / California

Most polluted cities in California, United States

103 measured cities ranked by PM2.5, last 30 days. Worst: Calexico at 23.0 µg/m³, #134 in the world.

#	City	µg/m³
1	Calexico California	23.0
2	Jurupa Valley California	12.9
3	Riverside California	12.3
4	Hanford California	11.9
5	Oceanside California	11.8
6	Corcoran California	11.0
7	Fontana California	11.0
8	Clovis California	10.9
9	Fresno California	10.7
10	Los Angeles California	10.6
11	Whittier California	10.3
12	Compton California	9.8
13	San Diego California	9.7
14	Richmond California	9.6
15	Tulare low-cost sensorsCalifornia	9.6
16	Hawthorne low-cost sensorsCalifornia	9.5
17	Glendora California	9.4
18	Chula Vista California	9.3
19	Madera California	9.2
20	Mission Viejo California	9.1
21	Arroyo Grande California	9.0
22	Merced California	9.0
23	Carson low-cost sensorsCalifornia	8.9
24	Porterville California	8.9
25	Bakersfield California	8.8
26	Santa Clarita California	8.8
27	Burbank California	8.7
28	Agoura low-cost sensorsCalifornia	8.6
29	Lake Elsinore California	8.5
30	Santa Monica low-cost sensorsCalifornia	8.5
31	El Cajon California	8.4
32	Anaheim California	8.3
33	Inglewood low-cost sensorsCalifornia	8.3
34	Poway California	8.2
35	Long Beach California	8.1
36	Orcutt California	8.0
37	San Jose California	8.0
38	Lomita low-cost sensorsCalifornia	7.9
39	Salinas California	7.9
40	Turlock California	7.9
41	Manteca California	7.7
42	San Leandro California	7.5
43	Torrance low-cost sensorsCalifornia	7.5
44	Pasadena low-cost sensorsCalifornia	7.3
45	Santa Cruz California	7.2
46	Yuba City California	7.2
47	Elk Grove low-cost sensorsCalifornia	7.0
48	South Lake Tahoe California	7.0
49	Victorville California	7.0
50	La Crescenta-Montrose low-cost sensorsCalifornia	7.0
51	Livermore California	6.9
52	Nipomo California	6.9
53	Brawley California	6.8
54	Prunedale low-cost sensorsCalifornia	6.8
55	Redwood City California	6.8
56	San Francisco California	6.8
57	Delano low-cost sensorsCalifornia	6.7
58	Simi Valley California	6.7
59	Stockton California	6.7
60	Fillmore California	6.6
61	Banning California	6.6
62	Davis California	6.6
63	Berkeley California	6.5
64	Oxnard California	6.5
65	Thousand Oaks California	6.5
66	Arden-Arcade California	6.5
67	Lincoln California	6.4
68	Temecula California	6.4
69	Vallejo California	6.4
70	Galt California	6.2
71	Concord California	6.0
72	Florin low-cost sensorsCalifornia	6.0
73	Huntington Beach low-cost sensorsCalifornia	6.0
74	Roseville California	6.0
75	Redding California	6.0
76	El Centro California	5.8
77	Oakland California	5.8
78	South San Francisco low-cost sensorsCalifornia	5.7
79	Gilroy California	5.6
80	Sacramento California	5.6
81	Seaside low-cost sensorsCalifornia	5.6
82	Ukiah California	5.3
83	Paradise California	5.2
84	Truckee California	5.2
85	Watsonville low-cost sensorsCalifornia	5.2
86	Modesto California	5.1
87	Windsor low-cost sensorsCalifornia	5.1
88	Tracy California	5.0
89	Chico California	4.9
90	Los Banos low-cost sensorsCalifornia	4.9
91	Ridgecrest California	4.9
92	Atascadero California	4.8
93	Indio California	4.7
94	San Rafael California	4.7
95	Hollister California	4.6
96	Goleta low-cost sensorsCalifornia	4.4
97	Lancaster California	4.4
98	Folsom California	4.2
99	Santa Rosa California	4.2
100	Palo Alto low-cost sensorsCalifornia	4.0
101	Lompoc California	3.6
102	Encinitas low-cost sensorsCalifornia	3.2
103	Vacaville California	3.2

Good 0–9.0Moderate 9.1+Unhealthy for sensitive groups 35.5+Unhealthy 55.5+Very unhealthy 125.5+Hazardous 225.5+No data

Estimated: cities without a monitor

California cities we can't measure, with model estimates for the last 7 days. Listed by population, not ranked: estimates aren't precise enough to rank. Model estimates from the Copernicus Atmosphere Monitoring Service (CAMS), adjusted to measured cities nearby where there are any. Adjusted, a single day lands within ×1.5 of what a monitor would read about two times in three; unadjusted, it can be off by half or double. Treat them as a guide, not a measurement.

City	7-day estimate	Band
Santa Ana estimated	≈ 8 µg/m³	Good
Irvine estimated	≈ 8 µg/m³	Good
Fremont estimated	≈ 9 µg/m³	Moderate
San Bernardino estimated	≈ 9 µg/m³	Good
Moreno Valley estimated	≈ 9 µg/m³	Good
Glendale estimated	≈ 12 µg/m³	Moderate
Garden Grove estimated	≈ 8 µg/m³	Good
Rancho Cucamonga estimated	≈ 12 µg/m³	Moderate
Corona estimated	≈ 11 µg/m³	Moderate
Palmdale estimated	≈ 6 µg/m³	Good
Hayward estimated	≈ 10 µg/m³	Moderate
Sunnyvale estimated	≈ 9 µg/m³	Good
Pomona estimated	≈ 10 µg/m³	Moderate
Escondido estimated	≈ 11 µg/m³	Moderate
Valencia estimated	≈ 7 µg/m³	Good
Orange estimated	≈ 8 µg/m³	Good
Fullerton estimated	≈ 12 µg/m³	Moderate
East Los Angeles estimated	≈ 11 µg/m³	Moderate
Santa Clara estimated	≈ 9 µg/m³	Good
El Monte estimated	≈ 11 µg/m³	Moderate
Carlsbad estimated	≈ 11 µg/m³	Moderate
Downey estimated	≈ 11 µg/m³	Moderate
Costa Mesa estimated	≈ 8 µg/m³	Good
Fairfield estimated	≈ 6 µg/m³	Good
Antioch estimated	≈ 9 µg/m³	Good
Murrieta estimated	≈ 10 µg/m³	Moderate
West Covina estimated	≈ 12 µg/m³	Moderate
Norwalk estimated	≈ 12 µg/m³	Moderate
Daly City estimated	≈ 7 µg/m³	Good
Santa Maria estimated	≈ 8 µg/m³	Good
San Mateo estimated	≈ 7 µg/m³	Good
Rialto estimated	≈ 9 µg/m³	Good
Vista estimated	≈ 11 µg/m³	Moderate
Ventura estimated	≈ 6 µg/m³	Good
South Gate estimated	≈ 12 µg/m³	Moderate
Hesperia estimated	≈ 5 µg/m³	Good
San Marcos estimated	≈ 11 µg/m³	Moderate
Westminster estimated	≈ 8 µg/m³	Good
Santa Barbara estimated	≈ 5 µg/m³	Good
Menifee estimated	≈ 10 µg/m³	Moderate

Updated 2026-10-01 10:07 UTC. Values are PM2.5 in µg/m³ (fine particles), the median of each city's monitors.