How often are air quality rankings updated?

Rankings are rebuilt every time the site is published, using the latest observations EPA AirNow has for each city. Individual city pages show the exact observation time behind each number.

Air Quality Rankings: Best & Worst US Cities (2026)

Q: Which US city has the best air quality?

Currently, Sioux Falls, SD has the best air quality in the United States with an AQI of 7 (Good). Rankings come from the latest EPA AirNow observations available when this page was published.

Q: Which US city has the worst air quality today?

Currently, Portland, OR has the highest pollution levels with an AQI of 167 (Unhealthy). Air quality can change significantly throughout the day and by season.

Q: How many US cities do you track for air quality?

We track EPA AirNow air quality observations for 145 cities across the United States, covering all 50 states plus Washington D.C.

August 2026: #1 cleanest city is Sioux Falls, SD (AQI 7). Ranked from the latest EPA AirNow observations. Find which US cities have the healthiest air.

Last updated August 5, 2026 · Real-time AQI from EPA AirNow monitoring stations

72 cities with Good air quality

68 cities with Moderate air quality

5 cities requiring caution

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Best Air Quality by US Region Today

Lowest AQI city in each region right now — useful for regional comparisons and relocation research.

Northeast

Providence, RIAQI 21

All Northeast cities →

Southeast

Baltimore, MDAQI 22

All Southeast cities →

Midwest

Sioux Falls, SDAQI 7

All Midwest cities →

Southwest

Mesa, AZAQI 35

All Southwest cities →

Mountain

Boise, IDAQI 28

All Mountain cities →

Pacific

Anchorage, AKAQI 8

All Pacific cities →

About These Rankings

Rankings are based on the most recent Air Quality Index (AQI) observations from EPA monitoring stations via the AirNow network. The AQI is calculated from measurements of five major pollutants: ground-level ozone, particulate matter (PM2.5 and PM10), carbon monoxide, sulfur dioxide, and nitrogen dioxide. Lower AQI values indicate cleaner air. Rankings are rebuilt from a fresh AirNow pull each time the site is published.

How to Read These Air Quality Rankings

Every city in this list is ranked by its Air Quality Index (AQI) — a single 0–500 number the U.S. EPA uses to report how clean or polluted the air is right now and what it means for your health. A lower AQI is better: cities near the top of the “Best Air Quality” list have the cleanest air today, while those flagged as “requiring caution” have elevated pollution that can affect sensitive groups. Because the AQI is reported on the same scale nationwide, you can compare any two cities directly — an AQI of 35 in one city means the same thing as an AQI of 35 in another.

The headline AQI for each city reflects whichever pollutant is highest at the moment — usually ground-level ozone (worst on hot, sunny afternoons) or PM2.5 fine particles (worst during wildfire smoke and winter inversions). That’s why a city’s rank can shift hour to hour and season to season. Use the color-coded scale below to translate any AQI value into a plain-English health recommendation.

Air Quality Index (AQI) Scale Explained

AQI	Category	What It Means for You
0–50	Good	Air quality is satisfactory, and air pollution poses little or no risk.
51–100	Moderate	Air quality is acceptable. However, there may be a risk for some people, particularly those who are unusually sensitive to air pollution.
101–150	Unhealthy for Sensitive Groups	Members of sensitive groups may experience health effects. The general public is less likely to be affected.
151–200	Unhealthy	Some members of the general public may experience health effects; members of sensitive groups may experience more serious health effects.
201–300	Very Unhealthy	Health alert: The risk of health effects is increased for everyone.
301–500	Hazardous	Health warning of emergency conditions: everyone is more likely to be affected.

A “good” AQI is 0–50. Most people only need to take precautions once the AQI rises above 100 (Unhealthy for Sensitive Groups), while a reading above 150 means everyone should consider limiting strenuous outdoor activity. Scale and health categories follow the EPA AirNow standard.

Popular City & State Air Quality Reports

Irvine, CA air quality 2025 →Irvine, CA air quality 2024 →Arizona air quality by city →Washington DC air quality →California air quality by city →Texas air quality by city →

Air Purifier & Monitor Buying Guides

Not sure which device fits your needs? Our hands-on guides break down the best picks by use case.

Best Air Purifiers Buying Guide →HEPA, CADR & room-size explained Best Air Quality Monitors →Track PM2.5 & AQI in your home Air Purifiers for Wildfire Smoke & PM2.5 →True-HEPA picks for smoke events Improving Indoor Air for Allergies & Pets →Reduce allergens, dander & dust

Complete 2026 Air Quality Rankings

Rank	City	State	AQI	Category
1	Sioux Falls	South Dakota	AQI 7	Good
2	Anchorage	Alaska	AQI 8	Good
3	Honolulu	Hawaii	AQI 19	Good
4	Providence	Rhode Island	AQI 21	Good
5	Baltimore	Maryland	AQI 22	Good
6	Virginia Beach	Virginia	AQI 23	Good
7	Norfolk	Virginia	AQI 23	Good
8	Erie	Pennsylvania	AQI 25	Good
9	Charlotte	North Carolina	AQI 28	Good
10	Atlantic City	New Jersey	AQI 28	Good
11	Boise	Idaho	AQI 28	Good
12	Burlington	Vermont	AQI 28	Good
13	Wilmington	Delaware	AQI 28	Good
14	Fargo	North Dakota	AQI 28	Good
15	Albany	New York	AQI 29	Good
16	West Palm Beach	Florida	AQI 31	Good
17	Lexington	Kentucky	AQI 32	Good
18	Manchester	New Hampshire	AQI 32	Good
19	Fort Lauderdale	Florida	AQI 33	Good
20	Worcester	Massachusetts	AQI 33	Good
21	Richmond	Virginia	AQI 33	Good
22	New Haven	Connecticut	AQI 33	Good
23	Raleigh	North Carolina	AQI 34	Good
24	Orlando	Florida	AQI 35	Good
25	Mesa	Arizona	AQI 35	Good
26	Boston	Massachusetts	AQI 35	Good
27	Springfield	Massachusetts	AQI 35	Good
28	Cambridge	Massachusetts	AQI 35	Good
29	Minneapolis	Minnesota	AQI 35	Good
30	St. Paul	Minnesota	AQI 35	Good
31	Allentown	Pennsylvania	AQI 36	Good
32	Nashville	Tennessee	AQI 37	Good
33	Hartford	Connecticut	AQI 37	Good
34	Columbia	South Carolina	AQI 37	Good
35	Irvine	California	AQI 39	Good
36	Tallahassee	Florida	AQI 39	Good
37	Yonkers	New York	AQI 39	Good
38	White Plains	New York	AQI 39	Good
39	San Jose	California	AQI 40	Good
40	Macon	Georgia	AQI 40	Good
41	Trenton	New Jersey	AQI 40	Good
42	San Francisco	California	AQI 41	Good
43	Sarasota	Florida	AQI 41	Good
44	Syracuse	New York	AQI 41	Good
45	Philadelphia	Pennsylvania	AQI 41	Good
46	Scranton	Pennsylvania	AQI 41	Good
47	Lubbock	Texas	AQI 42	Good
48	Columbus	Ohio	AQI 42	Good
49	Greensboro	North Carolina	AQI 42	Good
50	Winston-Salem	North Carolina	AQI 42	Good
51	Durham	North Carolina	AQI 43	Good
52	Lansing	Michigan	AQI 43	Good
53	Santa Fe	New Mexico	AQI 43	Good
54	St. Petersburg	Florida	AQI 44	Good
55	Birmingham	Alabama	AQI 44	Good
56	Montgomery	Alabama	AQI 44	Good
57	Atlanta	Georgia	AQI 45	Good
58	Miami	Florida	AQI 46	Good
59	Dayton	Ohio	AQI 46	Good
60	Savannah	Georgia	AQI 46	Good
61	Flint	Michigan	AQI 46	Good
62	Baton Rouge	Louisiana	AQI 46	Good
63	Jacksonville	Florida	AQI 47	Good
64	Pittsburgh	Pennsylvania	AQI 47	Good
65	Omaha	Nebraska	AQI 47	Good
66	Modesto	California	AQI 48	Good
67	Tampa	Florida	AQI 48	Good
68	Albuquerque	New Mexico	AQI 48	Good
69	Portland	Maine	AQI 48	Good
70	Billings	Montana	AQI 49	Good
71	Bakersfield	California	AQI 50	Good
72	Augusta	Georgia	AQI 50	Good
73	Santa Rosa	California	AQI 51	Moderate
74	New York	New York	AQI 51	Moderate
75	Grand Rapids	Michigan	AQI 51	Moderate
76	Newark	New Jersey	AQI 51	Moderate
77	Jersey City	New Jersey	AQI 51	Moderate
78	Phoenix	Arizona	AQI 51	Moderate
79	Scottsdale	Arizona	AQI 51	Moderate
80	Knoxville	Tennessee	AQI 51	Moderate
81	Charleston	South Carolina	AQI 51	Moderate
82	Los Angeles	California	AQI 52	Moderate
83	Sacramento	California	AQI 52	Moderate
84	Amarillo	Texas	AQI 52	Moderate
85	Springfield	Illinois	AQI 52	Moderate
86	Washington	District of Columbia	AQI 52	Moderate
87	Lincoln	Nebraska	AQI 52	Moderate
88	Charleston	West Virginia	AQI 52	Moderate
89	Harrisburg	Pennsylvania	AQI 53	Moderate
90	Fort Wayne	Indiana	AQI 53	Moderate
91	Louisville	Kentucky	AQI 53	Moderate
92	Oakland	California	AQI 54	Moderate
93	Cincinnati	Ohio	AQI 54	Moderate
94	Tucson	Arizona	AQI 54	Moderate
95	Memphis	Tennessee	AQI 54	Moderate
96	Pensacola	Florida	AQI 55	Moderate
97	Stockton	California	AQI 56	Moderate
98	Chicago	Illinois	AQI 56	Moderate
99	Fresno	California	AQI 57	Moderate
100	Visalia	California	AQI 57	Moderate
101	Indianapolis	Indiana	AQI 57	Moderate
102	San Diego	California	AQI 58	Moderate
103	Rockford	Illinois	AQI 58	Moderate
104	Cleveland	Ohio	AQI 58	Moderate
105	Akron	Ohio	AQI 58	Moderate
106	Detroit	Michigan	AQI 58	Moderate
107	Ann Arbor	Michigan	AQI 58	Moderate
108	Buffalo	New York	AQI 60	Moderate
109	Peoria	Illinois	AQI 60	Moderate
110	Kansas City	Missouri	AQI 60	Moderate
111	Little Rock	Arkansas	AQI 60	Moderate
112	Long Beach	California	AQI 61	Moderate
113	Aurora	Illinois	AQI 61	Moderate
114	Riverside	California	AQI 62	Moderate
115	St. Louis	Missouri	AQI 62	Moderate
116	Des Moines	Iowa	AQI 62	Moderate
117	Laredo	Texas	AQI 63	Moderate
118	New Orleans	Louisiana	AQI 64	Moderate
119	McAllen	Texas	AQI 65	Moderate
120	Brownsville	Texas	AQI 65	Moderate
121	Cheyenne	Wyoming	AQI 67	Moderate
122	Colorado Springs	Colorado	AQI 68	Moderate
123	Wichita	Kansas	AQI 68	Moderate
124	San Antonio	Texas	AQI 69	Moderate
125	Jackson	Mississippi	AQI 69	Moderate
126	Milwaukee	Wisconsin	AQI 70	Moderate
127	Madison	Wisconsin	AQI 70	Moderate
128	Las Vegas	Nevada	AQI 71	Moderate
129	Dallas	Texas	AQI 72	Moderate
130	Fort Worth	Texas	AQI 72	Moderate
131	Austin	Texas	AQI 74	Moderate
132	El Paso	Texas	AQI 74	Moderate
133	Houston	Texas	AQI 78	Moderate
134	Corpus Christi	Texas	AQI 78	Moderate
135	Fort Collins	Colorado	AQI 78	Moderate
136	Denver	Colorado	AQI 82	Moderate
137	Aurora	Colorado	AQI 82	Moderate
138	Reno	Nevada	AQI 85	Moderate
139	Salt Lake City	Utah	AQI 86	Moderate
140	Toledo	Ohio	AQI 89	Moderate
141	Seattle	Washington	AQI 117	Unhealthy for Sensitive Groups
142	Tacoma	Washington	AQI 122	Unhealthy for Sensitive Groups
143	Spokane	Washington	AQI 135	Unhealthy for Sensitive Groups
144	Vancouver	Washington	AQI 152	Unhealthy
145	Portland	Oregon	AQI 167	Unhealthy

Frequently Asked Questions About Air Quality Rankings

Which US city has the best air quality?

Currently, Sioux Falls, SD has the best air quality in the United States with an AQI of 7 (Good). Rankings come from the latest EPA AirNow observations available when this page was published.

Which US city has the worst air quality today?

Currently, Portland, OR has the highest pollution levels with an AQI of 167 (Unhealthy). Air quality can change significantly throughout the day and by season.

How often are these air quality rankings updated?

Rankings are rebuilt every time the site is published, using the latest observations EPA AirNow has for each city. We publish several times a month, so a ranking can be hours to a few days old — individual city pages show the exact observation time behind each number.

What is considered "good" air quality?

Air quality is considered "Good" when the AQI is between 0-50. At this level, air pollution poses little or no risk, and outdoor activities are safe for everyone including sensitive groups. Currently, 72 out of 145 cities have good air quality.

How many US cities do you track for air quality?

We track EPA AirNow air quality observations for 145 cities across the United States, covering all 50 states plus Washington D.C. Our data comes from EPA-certified monitoring stations that measure PM2.5, ozone, and other key pollutants.

Which states have the best air quality in the US?

States with consistently good air quality include Hawaii, Maine, Vermont, and other areas with low population density and fewer industrial sources. View our state-by-state air quality data for detailed rankings.

Is it safe to move to a city with moderate air quality?

Cities with moderate air quality (AQI 51-100) are generally safe for most people. However, sensitive groups including those with asthma, respiratory conditions, or heart disease should monitor local conditions. Check our health guides for specific recommendations.

What causes cities to have poor air quality?

Poor air quality is typically caused by vehicle emissions, industrial pollution, wildfires, weather patterns (like temperature inversions), and geographic factors. Cities in valleys or near industrial areas often experience higher pollution levels. Learn more about air pollution causes and health effects.