Air Quality Rankings for District Of Columbia (2026)
District Of Columbia has 1 cities tracked by EPA air-quality monitors, with a state-wide 5-year median AQI of 49 — 8 points more polluted than the national average of AQI 41. District of Columbia, District Of Columbia ranks #1 with the cleanest air (AQI 49, Grade C).
How District Of Columbia Compares
District Of Columbia has 1 cities tracked by EPA air-quality monitors, with a state-wide 5-year median AQI of 49 — 8 points more polluted than the national average of AQI 41. District of Columbia, District Of Columbia ranks #1 with the cleanest air (AQI 49, Grade C). The rankings below are computed from the EPA Air Quality System (AQS), which aggregates daily AQI readings from federally certified monitors into annual averages. Cities are sorted by 5-year median AQI (lowest = cleanest = #1). The 5-year window smooths out year-to-year volatility from weather and wildfire events.
District Of Columbia is on an improving trajectory: 1 of 1 monitored cities show measurably cleaner air over the past decade, against just 0 that are getting worse. That mirrors the broader national pattern of falling particulate and ozone pollution as cleaner vehicles, cleaner power generation, and tighter industrial standards take effect.
The dominant pollutant across 1 of 1 District Of Columbia city is Fine Particulate Matter (PM2.5). PM2.5 (fine particulate matter) is most often driven by combustion sources — vehicle exhaust, industrial emissions, residential wood burning, and increasingly wildfire smoke. It penetrates deep into lung tissue and the bloodstream and is the air pollutant most strongly linked to long-term health impacts.
The fastest-improving city in District Of Columbia is District of Columbia, District Of Columbia, with median AQI falling by 0.6 points per year. Steady improvement at that pace usually reflects fleet turnover (older diesels retiring), upwind power-plant retirements, or tighter regional emissions controls.
Full District Of Columbia Ranking
| # | City | 5yr Avg AQI | Current AQI | Worst Pollutant | Trend | Grade |
|---|---|---|---|---|---|---|
| 1 | District of Columbia, District Of Columbia | 49 | 50 | PM2.5 | Improving | C |
Air quality data for District Of Columbia is sourced from the EPA Air Quality System (AQS), which monitors outdoor air quality at thousands of stations nationwide.
Frequently Asked Questions
District of Columbia, District Of Columbia has the best air quality in District Of Columbia with a 5-year average AQI of 49 and a Grade C (63/100). Its dominant pollutant is Fine Particulate Matter (PM2.5) and the long-run trend is improving.
District Of Columbia has only 1 monitored area, so a "worst" ranking is not meaningful.
District Of Columbia has 1 cities with EPA air quality monitoring data, covering 2014-2023 of daily AQI measurements aggregated into annual averages.
District Of Columbia's state-wide 5-year median AQI is 49, 8 points more polluted than the national average of AQI 41. District Of Columbia is on an improving trajectory: 1 of 1 monitored cities show measurably cleaner air over the past decade, against just 0 that are getting worse. That mirrors the broader national pattern of falling particulate and ozone pollution as cleaner vehicles, cleaner power generation, and tighter industrial standards take effect.
Fine Particulate Matter (PM2.5) is the dominant pollutant in 1 of 1 monitored District Of Columbia cities. PM2.5 (fine particulate matter) is most often driven by combustion sources — vehicle exhaust, industrial emissions, residential wood burning, and increasingly wildfire smoke. It penetrates deep into lung tissue and the bloodstream and is the air pollutant most strongly linked to long-term health impacts.
District Of Columbia cities log an average of 6 days per year at "Unhealthy for Sensitive Groups" or worse, based on EPA monitor data over the last five years. Across all 1 District Of Columbia cities tracked, that totals 30 unhealthy days over the period.
Cities ranked by 5-year average AQI (lower is better). Grades factor in average AQI, trend direction, unhealthy days, and dominant pollutant.
The this entity category groups every U.S. air quality and pollution monitoring entity sharing this attribute. The list above is the data; the paragraphs below explain what the grouping means against the broader the EPA Air Quality System (AQS) distribution and how to read the relative rankings within the category.
For readers using this category as a starting point, the per-entity detail pages linked from the table above carry the underlying the EPA Air Quality System (AQS) data in full. The category-level view is the filter; the per-entity pages are the actual answer.
Source: EPA Outdoor Air Quality Data, 2026.