GIS Map
RankingsIndianaWorst air quality

Counties with the Worst Air Quality in Indiana

The top 25 of 33 Indiana counties on GIS Map, ranked by median Air Quality Index, counting only counties that host an EPA air monitor.

#CountyMedian AQI
1Marion County
54
2Lake County
52
3Clark County
47
4Vigo County
47
5Vanderburgh County
46
6Allen County
45
7Elkhart County
45
8St. Joseph County
45
9Bartholomew County
44
10Delaware County
44
11Hamilton County
44
12Howard County
44
13Porter County
44
14Floyd County
43
15Greene County
42
16Madison County
42
17LaPorte County
41
18Dubois County
39
19Perry County
39
20Knox County
38
21Warrick County
38
22Brown County
37
23Posey County
37
24Boone County
36
25Carroll County
36

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 Indiana”, https://gismap.land/rankings/indiana/worst-air-quality-counties. Figures from EPA Air Quality Index annual summary (2024).

More Indiana 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