Discover the consistently clean air all year based on comprehensive air quality data.
"Year round" means no bad season, so the ranking metric here is each city's worst season, not its average. Honolulu, HI comes out first: its worst season still has a median AQI of only 34 (its best season is 23, a spread of 11 points), with 97.6% of 2557 measured days at AQI 50 or below and 0% above AQI 100.
| # | City (EPA area) | Worst season median AQI | Best season median AQI | Seasonal spread | Good days | Days over 100 |
|---|---|---|---|---|---|---|
| 1 | Honolulu, HIUrban Honolulu, HI | 34 | 23 | 11 | 97.6% | 0% |
| 2 | Santa Rosa, CASanta Rosa, CA | 36 | 25 | 11 | 86.5% | 0.4% |
| 3 | Lubbock, TXLubbock, TX | 37 | 16 | 21 | 87.7% | 0.2% |
| 4 | Billings, MTBillings, MT | 39 | 31 | 8 | 81.4% | 0.9% |
| 5 | Manchester, NHManchester-Nashua, NH | 43 | 32 | 11 | 89.8% | 0.4% |
| 6 | Burlington, VTBurlington-South Burlington, VT | 43 | 33 | 10 | 82% | 0.4% |
| 7 | Syracuse, NYSyracuse, NY | 43 | 31 | 12 | 81.9% | 0.5% |
| 8 | Sioux Falls, SDSioux Falls, SD | 44 | 33 | 11 | 78.4% | 1.6% |
| 9 | Erie, PAErie, PA | 44 | 34 | 10 | 76.5% | 0.4% |
| 10 | Anchorage, AKAnchorage, AK | 44 | 19 | 25 | 75.6% | 0.9% |
| 11 | Flint, MIFlint, MI | 44 | 35 | 9 | 71% | 0.9% |
| 12 | Atlantic City, NJAtlantic City-Hammonton, NJ | 45 | 33 | 12 | 79.9% | 0.3% |
| 13 | Fargo, NDFargo, ND-MN | 45 | 34 | 11 | 73.2% | 1.8% |
| 14 | Norfolk, VAVirginia Beach-Norfolk-Newport News, VA-NC | 46 | 36 | 10 | 74.1% | 0.2% |
| 15 | Virginia Beach, VAVirginia Beach-Norfolk-Newport News, VA-NC | 46 | 36 | 10 | 74.1% | 0.2% |
| 16 | Charleston, WVCharleston, WV | 46 | 37 | 9 | 73.2% | 0% |
| 17 | Rochester, NYRochester, NY | 46 | 34 | 12 | 71.5% | 0.8% |
| 18 | Albany, NYAlbany-Schenectady-Troy, NY | 46 | 35 | 11 | 70.7% | 0.7% |
| 19 | Springfield, MASpringfield, MA | 46 | 39 | 7 | 66.9% | 0.7% |
| 20 | Portland, MEPortland-South Portland, ME | 47 | 33 | 14 | 75.3% | 0.7% |
| 21 | Scranton, PAScranton--Wilkes-Barre--Hazleton, PA | 47 | 36 | 11 | 72.6% | 0.5% |
| 22 | Durham, NCDurham-Chapel Hill, NC | 47 | 41 | 6 | 65.4% | 0.2% |
| 23 | Madison, WIMadison, WI | 47 | 39 | 8 | 61.6% | 1.5% |
| 24 | Worcester, MAWorcester, MA-CT | 48 | 35 | 13 | 70.9% | 0.4% |
| 25 | Charleston, SCCharleston-North Charleston, SC | 48 | 43 | 5 | 63.7% | 0.2% |
Source: EPA's published Daily AQI by CBSA files, grouped into meteorological seasons over the whole record. Only areas with at least 300 measured days in every one of the four seasons are ranked. 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.
Two cities can post the same annual average and feel completely different to live in. One is mild all twelve months; the other is pristine for half the year and unbreathable for the other half, usually because of a summer ozone season or a winter inversion. The spread column is that difference in a single number — the gap between the city's best and worst season median AQI. A small spread is what most people actually mean by good year-round air.
To see which season a given city loses, open its seasonal breakdown or compare two places directly on the comparison pages.
Seasonal air quality varies significantly. These cities maintain good air quality during this season.
Cities are ranked based on AQI levels, dominant pollutants, seasonal patterns, and specific factors relevant to this category.