Metro ranking · 2025

Cleanest Metro Areas in the US (2025)

The metropolitan areas where residents breathe Good air most often, ranked by share of Good days from EPA Air Quality System monitoring.

100.0%
#1 Evanston, WY
50
Metros ranked

Evanston, WY leads the 2025 cleanest-metro list among 50 ranked CBSAs (100.0% Good-day share)

According to the U.S. EPA Air Quality System, this ranking orders Core-Based Statistical Areas with at least 200 monitored days in 2025 by the highest share of days in the Good AQI band. It describes a historical reporting year, not today's air quality. For current conditions and alerts, use AirNow.

Data source EPA Air Quality System (AQS)

Evanston, WY ranks #1 of 50 metros for Good-day share at 100.0% with median AQI 9.
Metros ranked
Metros ranked: 50
#1 days monitored
#1 days monitored: 269

Metro figures aggregate the EPA monitors across each Core-Based Statistical Area. Only metros monitored at least 200 days are ranked, so the list reflects sustained clean air rather than a short monitoring window. See the methodology for how metro AQI is computed.

from the compiled EPA AQS release in this database.

Top 12 cleanest-air metros

Share of monitored days rated Good (AQI 0–50)

  1. 1 Evanston, WY 100%
  2. 2 Santa Rosa, CA 100%
  3. 3 Show Low, AZ 99.5%
  4. 4 Clearlake, CA 99.2%
  5. 5 Vallejo-Fairfield, CA 99.2%
  6. 6 Taos, NM 98.9%
  7. 7 Bozeman, MT 98.1%
  8. 8 Kahului-Wailuku-Lahaina, HI 98.1%
  9. 9 Mayaguez, PR 97.8%
  10. 10 Rockland, ME 97.8%
  11. 11 Kinston, NC 97.6%
  12. 12 Mount Vernon-Anacortes, WA 97.5%

Good-day share · EPA Air Quality System

# Metro area Good days Median AQI
1 Evanston, WY 100.0% 9
2 Santa Rosa, CA 100.0% 9
3 Show Low, AZ 99.5% 13
4 Clearlake, CA 99.2% 31
5 Vallejo-Fairfield, CA 99.2% 33
6 Taos, NM 98.9% 16
7 Bozeman, MT 98.1% 11
8 Kahului-Wailuku-Lahaina, HI 98.1% 21
9 Mayaguez, PR 97.8% 9
10 Rockland, ME 97.8% 33
11 Kinston, NC 97.5% 35
12 Mount Vernon-Anacortes, WA 97.5% 25
13 Aberdeen, WA 97.3% 22
14 Urban Honolulu, HI 97.3% 29
15 Concord, NH 96.7% 37
16 Arkadelphia, AR 96.7% 34
17 Sevierville, TN 96.7% 40
18 Hailey, ID 96.6% 17
19 Morehead City, NC 96.2% 35
20 Vineyard Haven, MA 95.9% 35
21 Palatka, FL 95.6% 21
22 Bremerton-Silverdale, WA 95.5% 22
23 Lakeland-Winter Haven, FL 95.5% 34
24 Effingham, IL 95.5% 35
25 St. Marys, PA 95.3% 36
26 Tupelo, MS 95.0% 38
27 Sebring, FL 94.9% 35
28 Lake Havasu City-Kingman, AZ 94.8% 17
29 Quincy, IL-MO 94.7% 38
30 Watertown-Fort Drum, NY 94.7% 34
31 Meridian, MS 94.6% 35
32 Somerset, PA 94.5% 36
33 Blacksburg-Christiansburg-Radford, VA 94.4% 37
34 Sebastian-Vero Beach, FL 94.1% 37
35 Bellingham, WA 94.0% 31
36 Crestview-Fort Walton Beach-Destin, FL 93.9% 36
37 Steamboat Springs, CO 93.7% 22
38 Barnstable Town, MA 93.7% 36
39 Olympia-Tumwater, WA 93.5% 27
40 Cañon City, CO 93.4% 23
41 Oxford, NC 93.3% 39
42 Ithaca, NY 93.2% 35
43 Columbia, MO 93.2% 37
44 Pierre, SD 93.0% 18
45 Lawrence, KS 92.9% 37
46 Lubbock, TX 92.9% 24
47 Twin Falls, ID 92.9% 26
48 Pahrump, NV 92.6% 26
49 Havre, MT 92.1% 14
50 Wabash, IN 92.0% 34

Source: U.S. Environmental Protection Agency (EPA), Air Quality System (AQS). Good-day share is the share of monitored days with AQI at or below 50; metros monitored 200+ days only. U.S. Environmental Protection Agency (EPA), Air Quality System (AQS). Good-day share is the share of monitored days with AQI at or below 50; metros monitored 200+ days only.

Every figure on PlainAirData is rendered directly from EPA AQS air-quality monitoring data, no number is typed in by an editor. This page draws directly on EPA AQS air-quality monitoring data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.