Localized air quality events, such as wildfires that create smoke, 
may not be reflected in the data presented.

LOS ANGELES COUNTY

1. Central L.A.

2. Northwest Coastal L.A. County

3. Southwest Coastal L.A. County

4. South Coastal L.A. County

5. Southeast Los Angeles County

6. West San Fernando Valley

7. East San Fernando Valley

8. West San Gabriel Valley

9. East San Gabriel Valley 1

10. Pomona/Walnut Valley 1

11. South San Gabriel Valley

12. South Central L.A. County

13. Santa Clarita Valley

14. Antelope Valley

15. San Gabriel Mountains

ORANGE COUNTY

1. North Orange County

2. Central Orange County

3. North Coastal Orange County

4. Saddleback Valley

5. Central Coastal Orange County

6. Capistrano Valley

RIVERSIDE COUNTY

1. Norco/Corona

2. Metropolitan Riverside Area 1

3. Perris Valley

4. Lake Elsinore Area

5. Temecula Valley

6. Anza

7. Hemet/San Jacinto Valley

8. San Gorgonio Pass

9. Coachella Valley 1

10. East Riverside County

SAN BERNARDINO COUNTY

1. Northwest San Bernardino Valley

2. Southwest San Bernardino Valley

3. Central San Bernardino Valley 1

4. East San Bernardino Valley

5. East San Bernardino Mountains

6. Central San Bernardino Mountains

7. West San Bernardino Mountains