Top 25 Cities for Air Quality

The cleanest cities based on average AQI measurements and air quality data.

The short answer

Across the US metro areas EPA published a full 2025 AQI record for, Santa Rosa, CA had the highest share of Good-air days: 365 of 365 days (100%) at AQI 50 or below, median AQI 9, with 0 days above AQI 100. The 25 cleanest are ranked below on the same measure.

US cities ranked from EPA annual AQI summaries for 2025
#City (EPA area)Good days (2025)Median AQIDays over 100Days over 150Main pollutantAQI now
1Santa Rosa, CASanta Rosa, CA365 / 365 (100%)900coarse dust (PM10)6
2Honolulu, HIUrban Honolulu, HI355 / 365 (97.3%)2900ground-level ozone28
3Lubbock, TXLubbock, TX314 / 338 (92.9%)2421fine particulate matter (PM2.5)4
4San Jose, CASan Jose-Sunnyvale-Santa Clara, CA334 / 365 (91.5%)3900ground-level ozone48
5Burlington, VTBurlington-South Burlington, VT320 / 365 (87.7%)3841ground-level ozone26
6Billings, MTBillings, MT315 / 365 (86.3%)3800ground-level ozone58
7Manchester, NHManchester-Nashua, NH310 / 365 (84.9%)3840ground-level ozone12
8Syracuse, NYSyracuse, NY305 / 365 (83.6%)3640ground-level ozone36
9Flint, MIFlint, MI252 / 303 (83.2%)3830ground-level ozone54
10Atlantic City, NJAtlantic City-Hammonton, NJ300 / 365 (82.2%)3610ground-level ozone21
11Worcester, MAWorcester, MA-CT296 / 365 (81.1%)3910ground-level ozone17
12Sioux Falls, SDSioux Falls, SD294 / 364 (80.8%)3640ground-level ozone19
13Amarillo, TXAmarillo, TX286 / 365 (78.4%)4200ground-level ozone20
14Santa Fe, NMSanta Fe, NM286 / 365 (78.4%)4400ground-level ozone26
15Norfolk, VAVirginia Beach-Norfolk-Newport News, VA-NC285 / 365 (78.1%)4110fine particulate matter (PM2.5)24
16Virginia Beach, VAVirginia Beach-Norfolk-Newport News, VA-NC285 / 365 (78.1%)4110fine particulate matter (PM2.5)24
17Anchorage, AKAnchorage, AK283 / 365 (77.5%)2730fine particulate matter (PM2.5)18
18Charleston, WVCharleston, WV281 / 365 (77%)3900fine particulate matter (PM2.5)22
19Erie, PAErie, PA280 / 365 (76.7%)3410fine particulate matter (PM2.5)28
20Springfield, MASpringfield, MA279 / 365 (76.4%)4050ground-level ozone17
21Fargo, NDFargo, ND-MN275 / 361 (76.2%)37117ground-level ozone18
22Cheyenne, WYCheyenne, WY274 / 365 (75.1%)4510ground-level ozone27
23Greensboro, NCGreensboro-High Point, NC272 / 365 (74.5%)4200fine particulate matter (PM2.5)17
24Rochester, NYRochester, NY271 / 365 (74.2%)3970ground-level ozone—
25Portland, MEPortland-South Portland, ME270 / 365 (74%)4061ground-level ozone13

Figures are EPA's published annual AQI summaries by metropolitan area (Annual AQI by CBSA, 2019–2025), retrieved 2026-09-07. The daily AQI EPA summarises is the highest value any monitor in the area reported that day, so these are metro-area readings, not statewide or rural ones. Only cities with at least 300 reported days in 2025 are ranked — a partial year cannot be compared fairly against a full one — and cities in areas EPA publishes no summary for are left out rather than given an estimated value. "AQI now" is the latest AirNow observation at build time and is blank where AirNow has none.

How to read these numbers

The ranking metric is the share of monitored days at AQI 0–50. It rewards cities that are clean most of the time, which is what matters for day-to-day breathing. It is not the same as ranking by median AQI: a city can have a low median and still lose days to a wildfire week, which is why the "days over 100" and "days over 150" columns are shown alongside it.

EPA reports the AQI per metropolitan area, and each day's value is the highest reading from any monitor in that area. That makes the figures conservative for a large metro — one bad monitor sets the day — and it means rural areas without regulatory monitors do not appear at all.

About This Ranking

This ranking is based on Air Quality Index (AQI) measurements from EPA monitoring stations across the United States. Cities with lower AQI values have cleaner air and better air quality.

What Makes Air Quality Good?

Cities with good air quality typically have favorable geography (coastal locations, good ventilation), lower population density, fewer industrial sources, stricter environmental regulations, and less vehicle traffic.

Data Sources

Rankings are based on current AQI data from the EPA AirNow system, which monitors air quality continuously.