51 states ranked by average AQI (best first)
| # | State | AQI | Good Days | Unhealthy | PM2.5 | Pollutant | Trend |
|---|---|---|---|---|---|---|---|
| 1 | Hawaii(HI) | 28 | 320 | 2 | 4.5 | PM2.5 | → Stable |
| 2 | Maine(ME) | 30 | 310 | 2 | 5.2 | PM2.5 | → Stable |
| 3 | Vermont(VT) | 30 | 310 | 2 | 5.5 | PM2.5 | → Stable |
| 4 | North Dakota(ND) | 32 | 300 | 2 | 5.5 | PM2.5 | → Stable |
| 5 | New Hampshire(NH) | 34 | 290 | 3 | 5.8 | PM2.5 | → Stable |
| 6 | Alaska(AK) | 35 | 285 | 8 | 6.2 | PM2.5 | → Stable |
| 7 | South Dakota(SD) | 35 | 285 | 3 | 6 | PM2.5 | → Stable |
| 8 | Wyoming(WY) | 35 | 280 | 5 | 6 | Ozone | → Stable |
| 9 | Florida(FL) | 40 | 255 | 5 | 7 | Ozone | → Stable |
| 10 | Minnesota(MN) | 40 | 255 | 5 | 7 | PM2.5 | → Stable |
| 11 | Connecticut(CT) | 42 | 245 | 5 | 7.2 | Ozone | ↓ Improving |
| 12 | Massachusetts(MA) | 42 | 245 | 5 | 7.5 | PM2.5 | ↓ Improving |
| 13 | Oregon(OR) | 42 | 245 | 12 | 7.5 | PM2.5 | — Variable (wildfires) |
| 14 | Rhode Island(RI) | 42 | 248 | 5 | 7.5 | Ozone | → Stable |
| 15 | Washington(WA) | 42 | 245 | 12 | 7.2 | PM2.5 | — Variable (wildfires) |
| 16 | Wisconsin(WI) | 42 | 248 | 5 | 7.2 | PM2.5 | ↓ Improving |
| 17 | Iowa(IA) | 44 | 235 | 6 | 7.5 | Ozone | → Stable |
| 18 | Nebraska(NE) | 44 | 235 | 5 | 7.5 | Ozone | → Stable |
| 19 | Montana(MT) | 45 | 230 | 18 | 8 | PM2.5 | — Variable (wildfires) |
| 20 | South Carolina(SC) | 45 | 235 | 6 | 7.8 | Ozone | → Stable |
| 21 | Kansas(KS) | 46 | 228 | 6 | 7.8 | Ozone | → Stable |
| 22 | Arkansas(AR) | 48 | 220 | 8 | 8.5 | Ozone | ↓ Improving |
| 23 | Idaho(ID) | 48 | 225 | 15 | 8.5 | PM2.5 | — Variable (wildfires) |
| 24 | Mississippi(MS) | 48 | 225 | 6 | 8.2 | Ozone | → Stable |
| 25 | New Mexico(NM) | 48 | 225 | 8 | 7.5 | Ozone | → Stable |
| 26 | New York(NY) | 48 | 222 | 8 | 8.5 | PM2.5 | ↓ Improving |
| 27 | North Carolina(NC) | 48 | 225 | 8 | 8.2 | Ozone | ↓ Improving |
| 28 | Oklahoma(OK) | 48 | 225 | 6 | 8.2 | Ozone | → Stable |
| 29 | Virginia(VA) | 48 | 225 | 8 | 8.5 | Ozone | ↓ Improving |
| 30 | West Virginia(WV) | 48 | 228 | 6 | 8.5 | PM2.5 | ↓ Improving |
| 31 | Delaware(DE) | 50 | 210 | 10 | 9 | PM2.5 | ↓ Improving |
| 32 | District of Columbia(DC) | 50 | 210 | 10 | 9 | Ozone | ↓ Improving |
| 33 | Michigan(MI) | 50 | 215 | 10 | 9 | PM2.5 | ↓ Improving |
| 34 | New Jersey(NJ) | 50 | 212 | 10 | 9 | Ozone | ↓ Improving |
| 35 | Alabama(AL) | 52 | 200 | 12 | 9.5 | PM2.5 | ↓ Improving |
| 36 | Illinois(IL) | 52 | 200 | 12 | 9.5 | PM2.5 | ↓ Improving |
| 37 | Kentucky(KY) | 52 | 205 | 12 | 9.5 | PM2.5 | ↓ Improving |
| 38 | Maryland(MD) | 52 | 200 | 12 | 9.5 | Ozone | ↓ Improving |
| 39 | Missouri(MO) | 52 | 205 | 10 | 9.5 | PM2.5 | ↓ Improving |
| 40 | Ohio(OH) | 52 | 205 | 12 | 9.8 | PM2.5 | ↓ Improving |
| 41 | Tennessee(TN) | 52 | 205 | 10 | 9.2 | Ozone | ↓ Improving |
| 42 | Colorado(CO) | 55 | 195 | 15 | 9 | Ozone | → Stable |
| 43 | Georgia(GA) | 55 | 195 | 15 | 9.8 | Ozone | ↓ Improving |
| 44 | Indiana(IN) | 55 | 195 | 15 | 9.8 | PM2.5 | ↓ Improving |
| 45 | Louisiana(LA) | 55 | 195 | 12 | 9.5 | Ozone | → Stable |
| 46 | Pennsylvania(PA) | 55 | 195 | 15 | 10.2 | PM2.5 | ↓ Improving |
| 47 | Nevada(NV) | 58 | 185 | 18 | 10 | PM10 | → Stable |
| 48 | Texas(TX) | 58 | 188 | 18 | 9.8 | Ozone | → Stable |
| 49 | Utah(UT) | 62 | 175 | 25 | 11 | PM2.5 | → Stable |
| 50 | Arizona(AZ) | 65 | 168 | 28 | 10.5 | PM10 | → Stable |
| 51 | California(CA) | 78 | 130 | 65 | 13.5 | Ozone | — Slowly improving |