Air quality in United States

Air quality in California today

Updated Sun, 25 Oct 2026 17:13:57 GMT

Moderate: average US AQI 51 across 107 cities in California Worst now: Concord (71); cleanest: Lancaster (19).

Live US AQI, PM2.5 and ozone for cities across California, compared with the United States average.

Average US AQI: 51 Moderate
United States average: 48 747 cities
Most polluted now: Concord AQI 71
Cleanest now: Lancaster AQI 19
Cities above 100: 0

Air quality in California today

Right now the modelled air quality in California averages a US AQI of 51 (Moderate) across the 107 cities we track. By category: 36 Good, 71 Moderate (of 107).

That is close to the United States average of 48, ranking 39 of 51 states from cleanest to most polluted.

Concord has the worst air at 71 (PM2.5 24 µg/m³), and Lancaster the cleanest at 19. No tracked city is above 100, so no group needs to change plans.

California cities by AQI (most polluted first)

City	US AQI	Category	PM2.5 µg/m³	PM10 µg/m³	Ozone µg/m³
Concord	71	Moderate	24.3	26	48
Antioch	71	Moderate	24.3	26	48
Pittsburg	71	Moderate	24.3	26	48
Walnut Creek	71	Moderate	24.3	26	48
Brentwood	71	Moderate	24.3	26	48
Oakley	71	Moderate	24.3	26	48
Los Angeles	64	Moderate	15.3	16	55
Oakland	64	Moderate	14.9	17	66
East Los Angeles	64	Moderate	15.3	16	55
Vallejo	64	Moderate	14.9	17	66
Berkeley	64	Moderate	14.9	17	66
Downey	64	Moderate	15.3	16	55
Inglewood	64	Moderate	15.3	16	55
Richmond	64	Moderate	14.9	17	66
Redondo Beach	64	Moderate	15.3	16	55
Gardena	64	Moderate	15.3	16	55
San Pablo	64	Moderate	14.9	17	66
Hercules	64	Moderate	14.9	17	66
San Diego	60	Moderate	10.9	13	81
Coronado	60	Moderate	10.9	13	81
Anaheim	59	Moderate	7.9	8	71
Huntington Beach	59	Moderate	7.9	8	71
Glendale	59	Moderate	7.9	8	71
Garden Grove	59	Moderate	7.9	8	71
Pasadena	59	Moderate	7.9	8	71
Fullerton	59	Moderate	7.9	8	71
El Monte	59	Moderate	7.9	8	71
Costa Mesa	59	Moderate	7.9	8	71
West Covina	59	Moderate	7.9	8	71
Norwalk	59	Moderate	7.9	8	71
Burbank	59	Moderate	7.9	8	71
Whittier	59	Moderate	7.9	8	71
Fountain Valley	59	Moderate	7.9	8	71
Cypress	59	Moderate	7.9	8	71
Brea	59	Moderate	7.9	8	71
Monrovia	59	Moderate	7.9	8	71
Stockton	58	Moderate	10.5	12	62
San Francisco	57	Moderate	14.3	16	39
Daly City	57	Moderate	14.3	16	39
San Mateo	57	Moderate	14.3	16	39
Mission Viejo	57	Moderate	7.2	8	71
San Clemente	57	Moderate	7.2	8	71
Belmont	57	Moderate	14.3	16	39
Fremont	56	Moderate	8.2	10	72
Hayward	56	Moderate	8.2	10	72
Union City	56	Moderate	8.2	10	72
Dublin	56	Moderate	8.2	10	72
Newark	56	Moderate	8.2	10	72
Monterey	56	Moderate	13.1	14	72
Ashland	56	Moderate	8.2	10	72
San Jose	54	Moderate	8.6	10	89
Fresno	54	Moderate	11.7	13	81
Long Beach	54	Moderate	14.7	15	61
Santa Ana	54	Moderate	14.7	15	61
Irvine	54	Moderate	14.7	15	61
Sunnyvale	54	Moderate	8.6	10	89
Torrance	54	Moderate	14.7	15	61
Orange	54	Moderate	14.7	15	61
Santa Clara	54	Moderate	8.6	10	89
Clovis	54	Moderate	11.7	13	81
Carson	54	Moderate	14.7	15	61
Newport Beach	54	Moderate	14.7	15	61
Sacramento	53	Moderate	17.4	20	48
Bakersfield	53	Moderate	7.1	14	63
West Sacramento	53	Moderate	17.4	20	48
Ontario	52	Moderate	3.6	4	76
Pomona	52	Moderate	3.6	4	76
Yorba Linda	52	Moderate	3.6	4	76
Walnut	52	Moderate	3.6	4	76
Santa Rosa	51	Moderate	6.2	7	84
Windsor	51	Moderate	6.2	7	84
Oceanside	50	Good	5.5	6	91
Escondido	50	Good	5.5	6	91
Carlsbad	50	Good	5.5	6	91
Vista	50	Good	5.5	6	91
San Luis Obispo	46	Good	7.9	16	68
Woodland	45	Good	11.2	13	54
Paso Robles	44	Good	6.5	16	76
Temecula	43	Good	3.7	4	87
Murrieta	43	Good	3.7	4	87
Menifee	43	Good	3.7	4	87
Redding	40	Good	6.9	7	66
Thousand Oaks	39	Good	2.2	3	90
Simi Valley	39	Good	2.2	3	90
Riverside	36	Good	1.9	2	90
Chula Vista	36	Good	1.9	4	94
San Bernardino	36	Good	1.9	2	90
Fontana	36	Good	1.9	2	90
Moreno Valley	36	Good	1.9	2	90
Santa Clarita	36	Good	2.2	3	81
Rancho Cucamonga	36	Good	1.9	2	90
Corona	36	Good	1.9	2	90
Valencia	36	Good	2.2	3	81
El Cajon	36	Good	1.9	4	94
Rialto	36	Good	1.9	2	90
Redlands	36	Good	1.9	2	90
Eastvale	36	Good	1.9	2	90
Highland	36	Good	1.9	2	90
Spring Valley	36	Good	1.9	4	94
Lincoln	32	Good	4.9	6	75
Oxnard	30	Good	8.1	9	66
Ventura	30	Good	8.1	9	66
Eureka	30	Good	5.6	8	74
Yuba City	29	Good	4.3	5	61
Victorville	26	Good	1.1	1	90
Coachella	23	Good	1.2	2	80
Lancaster	19	Good	1.6	2	77

What the US AQI numbers mean

US AQI	Category	What it means
0-50	Good	Air quality is satisfactory and poses little or no risk; a good time for outdoor activity.
51-100	Moderate	Acceptable for most people. Unusually sensitive people should consider shortening long or heavy exertion outdoors.
101-150	Unhealthy for Sensitive Groups	People with heart or lung disease, older adults, children and teens should cut back on prolonged or heavy exertion outdoors.
151-200	Unhealthy	Everyone should reduce prolonged or heavy exertion outdoors; sensitive groups should avoid it and keep windows closed.
201-300	Very Unhealthy	Health alert: everyone should avoid prolonged or heavy exertion outdoors, and sensitive groups should stay indoors.
301-500	Hazardous	Emergency conditions: everyone should avoid all outdoor physical activity and stay indoors with filtered air if possible. The scale tops out at 500; heavier dust or smoke is shown as 500.

Modelled by CAMS (Copernicus) via Open-Meteo, refreshed twice a day; read hour by hour from the forecast.

Cities in California

Data: Open-Meteo Air Quality API, Copernicus Atmosphere Monitoring Service (CAMS).

Air quality in California today

Air quality in California today

California cities by AQI (most polluted first)

What the US AQI numbers mean

Cities in California

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