Miami Air Quality in 2021
In 2021, Miami's air quality (Miami-Fort Lauderdale-West Palm Beach, FL area) had a median daily AQI of 52 (Moderate) across 365 monitored days. 3 days (0.8%) reached Unhealthy for Sensitive Groups or worse, 160 were Good, and the year's peak AQI was 135 (Unhealthy for Sensitive Groups). Fine particulate matter (PM2.5) set the daily AQI on 305 of those days. The cleanest month of 2021 was October (median AQI 43, 0 days above 100) and the worst was June (median 51, 1 day above 100, peak 119).
- Good: 43.8%
- Moderate: 55.3%
- Unhealthy for Sensitive Groups: 0.8%
- Unhealthy or worse: 0.0%
Reduce Indoor Ozone in Miami
Today's main pollutant in Miami is ground-level ozone (AQI 19). Important: standard HEPA filters do NOT remove ozone — only a purifier with a substantial activated-carbon bed adsorbs it. The biggest wins are cutting indoor sources (gas appliances, certain "ionizer" purifiers) and ventilating when outdoor ozone is low (early morning). A high-carbon unit helps with the gases and VOCs that linger indoors.
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How was Miami's air quality in 2021?
Moderate on a typical day: median AQI 52, with 3 days above AQI 100 out of 365 monitored — the 5th cleanest of 7 years on record for the area.
- ✓Peak AQI in 2021: 135 (Unhealthy for Sensitive Groups).
- ✓Fine particulate matter (PM2.5) was the main pollutant on 305 days.
- ✓Cleanest month: October; worst: June.
Frequently asked questions
What was the average AQI in Miami in 2021?▾
EPA's Air Quality System puts Miami's (Miami-Fort Lauderdale-West Palm Beach, FL) median daily AQI for 2021 at 52, which is Moderate. 3 days were Unhealthy for Sensitive Groups or worse and the year's highest AQI was 135.
Which month had the worst air quality in Miami in 2021?▾
The cleanest month of 2021 was October (median AQI 43, 0 days above 100) and the worst was June (median 51, 1 day above 100, peak 119).
Was 2021 a good or bad year for Miami's air?▾
Among the 7 years EPA has published for the area (2019–2025), 2021 ranks 5th cleanest by days above AQI 100. 2021's median of 52 is in line with the area's typical annual median of 51.
Miami month by month in 2021
Miami air quality month by month, 2021 (Miami-Fort Lauderdale-West Palm Beach, FL, EPA AQS daily AQI)
| Month | Days monitored | Median AQI | Days above 100 | Peak AQI | Main pollutant |
|---|---|---|---|---|---|
| January | 31 | 56 | 0 | 69 | PM2.5 |
| February | 28 | 55 | 0 | 67 | PM2.5 |
| March | 31 | 52 | 0 | 71 | PM2.5 |
| April | 30 | 54 | 0 | 84 | PM2.5 |
| May | 31 | 53 | 1 | 103 | PM2.5 |
| Juneworst | 30 | 51 | 1 | 119 | PM2.5 |
| July | 31 | 53 | 0 | 83 | PM2.5 |
| August | 31 | 49 | 0 | 92 | PM2.5 |
| September | 30 | 45 | 0 | 83 | PM2.5 |
| Octobercleanest | 31 | 43 | 0 | 73 | PM2.5 |
| November | 30 | 43 | 0 | 94 | PM2.5 |
| December | 31 | 49 | 1 | 135 | PM2.5 |
How 2021 compares
Among the 7 years EPA has published for the area (2019–2025), 2021 ranks 5th cleanest by days above AQI 100.
2021's median of 52 is in line with the area's typical annual median of 51.
Activity-specific thresholds: running, cycling, kids' sports.
Right now in Miami
The latest EPA AirNow observation puts Miami's AQI at 19 (O3). The figures above are multi-year annual statistics, not today's reading.
View current Miami air quality →Source: EPA Air Quality System (AQS) pre-generated Daily AQI by CBSA files — daily AQI by CBSA (Miami-Fort Lauderdale-West Palm Beach, FL), 2019–2025. Daily AQI per CBSA is the highest AQI reported by any monitor in the area that day; the defining parameter is the pollutant that set it. Month and season statistics pool every such day in the period across all years listed. Retrieved 2026-09-09.