Site

State

PM AQI* (ug/m3)

Thirty Third

AZ

43

West Phoenix

AZ

37

Portola

CA

34

John Day Dayton St

OR

29

Durango Complex

AZ

29

Mammoth Lakes

CA

29

Omak-Colville Tribe

WA

28

Salmon PM2.5

ID

27

Clinton, Chancy Park

IA

26

Libby Courthouse

MT

26