Miami Best & Worst AQI Days: Air Quality Guide

The worst air quality day on record for Miami (Miami-Fort Lauderdale-West Palm Beach, FL area) was January 1, 2024, when the daily AQI reached 197 (Unhealthy), set by fine particulate matter (PM2.5). Across 2,556 monitored days in 2019–2025, 6 of the 10 worst days were Unhealthy (AQI 151+) or worse; 9 of the 10 were driven by fine particulate matter (PM2.5) and 1 by ground-level ozone, and 3 of them fell in 2023. The cleanest day was September 1, 2019 at AQI 1 (Good); the 10 best days span 3 different years.

197
Worst day AQI
2024-01-01
1
Best day AQI
2019-09-01
6
Top-10 days at 151+
Unhealthy or worse
2,556
Days monitored
2019–2025

Extra Protection for Miami Homes

Air quality in Miami is moderate (AQI 54), with fine particles (PM2.5) the main concern. A True-HEPA purifier gives sensitive groups — kids, seniors and anyone with asthma or allergies — cleaner air indoors on days like today.

Recommended: Coway AP-1512HH MightyTrue HEPA + carbon · CADR ~246 CFM · rooms up to 361 sq ft

Check Price on Amazon →

As an Amazon Associate, we earn from qualifying purchases.

QUICK ANSWER

When were Miami's worst and best air quality days?

Worst: January 1, 2024, AQI 197 (Unhealthy, PM2.5). Best: September 1, 2019, AQI 1 (Good). Based on 2,556 EPA-monitored days in the Miami-Fort Lauderdale-West Palm Beach, FL area, 2019–2025.

  • 6 of the 10 worst days were Unhealthy (AQI 151+) or worse; the 10th-worst was AQI 135 (Unhealthy for Sensitive Groups).
  • Fine particulate matter (PM2.5) drove 9 of the 10 worst days.
  • 2023 accounts for 3 of the 10 worst days.

Frequently asked questions

What was the worst air quality day in Miami?

January 1, 2024: the Miami-Fort Lauderdale-West Palm Beach, FL area's daily AQI hit 197 (Unhealthy), driven by fine particulate matter (PM2.5). That is the highest of 2,556 monitored days in 2019–2025.

What was the best air quality day in Miami?

September 1, 2019, with a daily AQI of 1 (Good). The daily AQI is the highest reading from any monitor in the area, so even the cleanest day reflects the area's worst monitor.

What was Miami's worst air quality day in 2025?

March 20, 2025, AQI 113 (Unhealthy for Sensitive Groups), set by fine particulate matter (PM2.5).

Which pollutant causes Miami's worst air days?

Fine particulate matter (PM2.5) set the AQI on 9 of the 10 worst days; ground-level ozone on 1. The tables above list the defining pollutant for every day.

Miami's 10 worst air quality days, 2019–2025

Highest daily AQI recorded for the Miami-Fort Lauderdale-West Palm Beach, FL area (EPA AQS). The daily AQI is the highest reading from any monitor in the area that day.

#DateAQICategoryDefining pollutant
1 (2024 page)197UnhealthyPM2.5fine particulate matter (PM2.5)
2 (2024 page)190UnhealthyPM2.5fine particulate matter (PM2.5)
3 (2023 page)170UnhealthyPM2.5fine particulate matter (PM2.5)
4 (2024 page)162UnhealthyPM2.5fine particulate matter (PM2.5)
5 (2023 page)156UnhealthyPM2.5fine particulate matter (PM2.5)
6 (2023 page)154UnhealthyO3ground-level ozone
7 (2019 page)146Unhealthy for Sensitive GroupsPM2.5fine particulate matter (PM2.5)
8 (2020 page)142Unhealthy for Sensitive GroupsPM2.5fine particulate matter (PM2.5), in wildfire smoke season
9 (2022 page)136Unhealthy for Sensitive GroupsPM2.5fine particulate matter (PM2.5)
10 (2021 page)135Unhealthy for Sensitive GroupsPM2.5fine particulate matter (PM2.5)

Worst day of each year in Miami

The single highest-AQI day in each year on record. Click a year for its full month-by-month statistics.

YearWorst dayAQICategoryDefining pollutant
2019146Unhealthy for Sensitive GroupsPM2.5fine particulate matter (PM2.5)
2020142Unhealthy for Sensitive GroupsPM2.5fine particulate matter (PM2.5), in wildfire smoke season
2021135Unhealthy for Sensitive GroupsPM2.5fine particulate matter (PM2.5)
2022136Unhealthy for Sensitive GroupsPM2.5fine particulate matter (PM2.5)
2023170UnhealthyPM2.5fine particulate matter (PM2.5)
2024197UnhealthyPM2.5fine particulate matter (PM2.5)
2025113Unhealthy for Sensitive GroupsPM2.5fine particulate matter (PM2.5)

Miami's 10 best air quality days, 2019–2025

Lowest daily AQI recorded for the Miami-Fort Lauderdale-West Palm Beach, FL area. Ties are listed most recent first.

#DateAQICategoryDefining pollutant
1 (2019 page)1GoodCOcarbon monoxide
2 (2019 page)19GoodO3ground-level ozone
3 (2019 page)25GoodO3ground-level ozone
4 (2019 page)25GoodO3ground-level ozone, in peak ozone season
5 (2024 page)26GoodPM2.5fine particulate matter (PM2.5)
6 (2024 page)26GoodO3ground-level ozone, in peak ozone season
7 (2019 page)26GoodPM2.5fine particulate matter (PM2.5)
8 (2019 page)26GoodO3ground-level ozone, in peak ozone season
9 (2025 page)28GoodNO2nitrogen dioxide
10 (2024 page)28GoodO3ground-level ozone

Right now in Miami

The latest EPA AirNow observation puts Miami's AQI at 54 (PM2.5). The days above are historical records, 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.