#1
Kenner, LA
PM2.5: 7.6 Unhealthy Days: 0.3%
Grade B
72.9
Score
Most Improved Air Quality Cities in the US (2026)
See which 10 US cities cut their AQI the most in 2026 — ranked by EPA data.
How to read this ranking: Cities are ordered by their overall Clean Air Score (0-100), combining annual PM2.5 averages, unhealthy days, and 5-year trends. A higher score means consistently cleaner air and lower health risks. Want to know exactly how we calculate this? Read our full methodology.
#2
Westlake (RR name West Lake), LA
PM2.5: 9.1 Unhealthy Days: 0.3%
Grade C
64.5
Score
#3
Schiller Park, IL
PM2.5: 8.3 Unhealthy Days: 0%
Grade B
70.6
Score
#4
Not in a city, AL
PM2.5: 6.5 Unhealthy Days: 0%
Grade B
80.5
Score
#5
Indianapolis (Remainder), IN
PM2.5: 9.7 Unhealthy Days: 0.3%
Grade C
60.5
Score
#6
Lancaster, CA
PM2.5: 4.8 Unhealthy Days: 0%
Grade A
89
Score
#7
Dearborn, MI
PM2.5: 9.3 Unhealthy Days: 0.6%
Grade C
61.8
Score
#8
Providence, RI
PM2.5: 5.4 Unhealthy Days: 0%
Grade A
87.1
Score
#9
College Station, TX
PM2.5: 8.2 Unhealthy Days: 0.3%
Grade C
68.9
Score
#10
San Luis Obispo, CA
PM2.5: 3.9 Unhealthy Days: 0%
Grade A
89.4
Score
How do we rank cities?
Our Clean Air Score measures long-term air quality stability, factoring in annual PM2.5 levels, frequency of unhealthy days, and 5-year improvement trends. Data is sourced strictly from official EPA sensors.