RANKABLE EPA COUNTY AQI
Air Quality in ZIP 59620 - Helena, Montana
County-derived EPA air-quality evidence connected locally through National Data System.
Median AQI
45.0
Maximum AQI
93.0
Good-air-quality days
65.38%
Average PM2.5
5.602 ug/m3
NDS Air Quality Score
36.01
U.S. County Rank
753 of 1,049
Percentile
28.05
Grade
D
What the data means
ZIP 59620 is connected to governed EPA county-level air-quality evidence for Lewis and Clark.
ZIP ranking note: ZIPs are not separately ranked. The rank shown on this page is the associated county rank because the EPA AQI evidence used here is county-derived.
County context
Methodology
EPA AQI evidence is county-derived. NDS connects that evidence to ZIP geography where a governed county relationship exists. NDS does not claim that EPA directly ranks ZIP codes.