# Worst air quality in the US right now — live ranking

> Source: https://breathecheck.com/worst-air-quality-us/
> Which US metro has the worst air at this hour, updated hourly across 121 metros from EPA AirNow. Ranked live, with the coverage limits stated.

# Worst air quality in the US right now

Updated 14 Sep 2026, 22:12 UTC · LIVE refreshed hourly

Right now the worst air among the 121 metros BreatheCheck measures is Birmingham, AL at AQI 93 — Moderate. We measure 121 of roughly 380 US metropolitan areas, so this is the worst reading we can see, not a national maximum. A city we do not monitor can be worse at this moment and we would not know.

## Which US city has the worst air quality right now?

| # | Metro | AQI |

| 1 | AL Birmingham no page yet | 93 Moderate |

| 2 | SD Rapid City no page yet | 91 Moderate |

| 3 | GA Atlanta | 77 Moderate |

| 4 | TN Nashville | 74 Moderate |

| 5 | CA Riverside | 73 Moderate |

| 6 | CA Fresno | 70 Moderate |

| 7 | AZ Phoenix | 66 Moderate |

| 8 | AR Little Rock no page yet | 63 Moderate |

| 9 | CA San Diego | 61 Moderate |

| 10 | CA Los Angeles | 60 Moderate |

Every metro we track, cleanest included →

## Which state has the worst air quality right now?

A state is shown at its worst tracked metro. Where that rests on a single city, the count says so — one metro is not a state, and we are not going to pretend otherwise.

| State | Worst metro | AQI | Metros tracked |

| AL | Birmingham no page yet | 93 | 2 |

| SD | Rapid City no page yet | 91 | 2 |

| GA | Atlanta | 77 | 2 |

| TN | Nashville | 74 | 2 |

| CA | Riverside | 73 | 12 |

| AZ | Phoenix | 66 | 3 |

| AR | Little Rock no page yet | 63 | 2 |

| FL | Miami | 59 | 4 |

## Which metros have had the most bad-air days since we started recording?

Phoenix, AZ leads, with 19 of its 30 recorded days above AQI 100. Of the 118 metros that have a series, 57 have had at least one such day since 16 August 2026. A day counts at its highest hourly reading, from our own readings only — nothing back-filled, and readings above the 500 end of the scale held back.

| Metro | Days above 100 | Days recorded | Worst day |

| AZ Phoenix | 19 | 30 | 478 30 August 2026 |

| CA Riverside | 16 | 30 | 172 20 August 2026 |

| CA Fresno | 15 | 30 | 169 13 September 2026 |

| TX Dallas | 13 | 30 | 192 27 August 2026 |

| TX Fort Worth | 13 | 30 | 192 27 August 2026 |

| CO Denver | 13 | 30 | 156 27 August 2026 |

| CO Boulder | 13 | 30 | 156 26 August 2026 |

| TN Memphis | 12 | 28 | 182 8 September 2026 |

| CA Bakersfield | 12 | 30 | 143 20 August 2026 |

| TX Houston | 11 | 30 | 215 2 September 2026 |

| CA Los Angeles | 9 | 30 | 161 26 August 2026 |

| OK Oklahoma City | 9 | 30 | 156 25 August 2026 |

Ranked by days above 100, then by the worst single day. Each metro’s own page has its full day-by-day record. Why we keep our own →

## Why is this different from the annual “most polluted cities” lists?

An hourly ranking answers a different question from an annual one. At any given hour the top of this table is usually decided by what is burning or what is trapped under an inversion that morning — a metro can sit mid-table for eleven months and lead the country for a week.

Annual rankings move far less. The San Joaquin Valley and the Los Angeles basin appear near the top of long-run PM2.5 and ozone lists in most years, because their sources are geography and traffic rather than weather. If you are choosing where to live, the annual picture is the one that matters. If you are deciding whether to run today, this table is.

The official monitor and the sensors near you disagree →

## Questions

**Who has the worst air quality in the US right now?**

Among the 121 US metros we measure hourly, Birmingham, AL is highest at AQI 93 (Moderate). We do not track every US city, so this is the worst reading we can see, not a national maximum.

**What state currently has the worst air quality?**

We rank states by their worst tracked metro, which is a floor rather than a verdict — a state with one monitored metro is being judged on one city. The table above shows how many metros each state rests on.

**What are the 10 worst US cities for air pollution?**

The list above is the worst ten right now, which is a different question from the worst ten over time. Across the days we have recorded ourselves since 16 August 2026, the most days above AQI 100 were in Phoenix (19), Riverside (16), Fresno (15). That is weeks of our own readings, not a year: annual rankings are a different and longer measurement.

**What is the dirtiest country in the world?**

We do not measure it. This site covers US metros only, and we would rather say so than repeat a global ranking we have not verified.

Updated 14 Sep 2026, 22:12 UTC