GIS Map
RankingsOregonWorst air quality

Counties with the Worst Air Quality in Oregon

The top 21 of 21 Oregon counties on GIS Map, ranked by median Air Quality Index, counting only counties that host an EPA air monitor.

#CountyMedian AQI
1Grant County
49
2Harney County
46
3Lane County
44
4Jackson County
41
5Deschutes County
39
6Umatilla County
38
7Marion County
35
8Multnomah County
35
9Klamath County
33
10Washington County
33
11Clackamas County
30
12Josephine County
29
13Baker County
28
14Lake County
28
15Columbia County
26
16Jefferson County
26
17Linn County
25
18Crook County
24
19Union County
23
20Wallowa County
23
21Wasco County
23

Source: EPA Air Quality Index annual summary (2024). All counties with data are ranked. Estimates carry margins of error.

Citing this page: GIS Map, “Counties with the Worst Air Quality in Oregon”, https://gismap.land/rankings/oregon/worst-air-quality-counties. Figures from EPA Air Quality Index annual summary (2024).

More Oregon rankings

Richest citiesMost expensive homesMost affordable homesHighest rentMost educatedHighest poverty rateMost densely populatedLargest by populationYoungestOldest by median ageFastest-growingFastest-shrinkingFastest-growing since 2010WarmestColdestSnowiestWettestDriestHighest hazard risk countiesLowest hazard risk countiesHighest expected lossesHighest radon potentialCleanest airWorst drought