Atlanta Best & Worst AQI Days: Air Quality Guide
The worst air quality day on record for Atlanta (Atlanta-Sandy Springs-Roswell, GA area) was June 29, 2023, when the daily AQI reached 172 (Unhealthy), set by ground-level ozone, in peak ozone season. Across 2,557 monitored days in 2019–2025, 6 of the 10 worst days were Unhealthy (AQI 151+) or worse; 8 of the 10 were driven by ground-level ozone and 2 by fine particulate matter (PM2.5), and 3 of them fell in 2019. The cleanest day was February 15, 2021 at AQI 20 (Good); the 10 best days span 7 different years.
Extra Protection for Atlanta Homes
Air quality in Atlanta is moderate (AQI 59), 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 Mighty — True HEPA + carbon · CADR ~246 CFM · rooms up to 361 sq ft
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When were Atlanta's worst and best air quality days?
Worst: June 29, 2023, AQI 172 (Unhealthy, O3). Best: February 15, 2021, AQI 20 (Good). Based on 2,557 EPA-monitored days in the Atlanta-Sandy Springs-Roswell, GA area, 2019–2025.
- ✓6 of the 10 worst days were Unhealthy (AQI 151+) or worse; the 10th-worst was AQI 147 (Unhealthy for Sensitive Groups).
- ✓Ground-level ozone drove 8 of the 10 worst days.
- ✓2019 accounts for 3 of the 10 worst days.
Frequently asked questions
What was the worst air quality day in Atlanta?▾
June 29, 2023: the Atlanta-Sandy Springs-Roswell, GA area's daily AQI hit 172 (Unhealthy), driven by ground-level ozone, in peak ozone season. That is the highest of 2,557 monitored days in 2019–2025.
What was the best air quality day in Atlanta?▾
February 15, 2021, with a daily AQI of 20 (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 Atlanta's worst air quality day in 2025?▾
June 25, 2025, AQI 129 (Unhealthy for Sensitive Groups), set by ground-level ozone, in peak ozone season.
Which pollutant causes Atlanta's worst air days?▾
Ground-level ozone set the AQI on 8 of the 10 worst days; fine particulate matter (PM2.5) on 2. The tables above list the defining pollutant for every day.
Atlanta's 10 worst air quality days, 2019–2025
Highest daily AQI recorded for the Atlanta-Sandy Springs-Roswell, GA area (EPA AQS). The daily AQI is the highest reading from any monitor in the area that day.
| # | Date | AQI | Category | Defining pollutant |
|---|---|---|---|---|
| 1 | (2023 page) | 172 | Unhealthy | O3 — ground-level ozone, in peak ozone season |
| 2 | (2019 page) | 172 | Unhealthy | O3 — ground-level ozone |
| 3 | (2022 page) | 169 | Unhealthy | O3 — ground-level ozone, in peak ozone season |
| 4 | (2024 page) | 161 | Unhealthy | O3 — ground-level ozone, in peak ozone season |
| 5 | (2023 page) | 156 | Unhealthy | O3 — ground-level ozone, in peak ozone season |
| 6 | (2023 page) | 153 | Unhealthy | PM2.5 — fine particulate matter (PM2.5), in wildfire smoke season |
| 7 | (2022 page) | 150 | Unhealthy for Sensitive Groups | O3 — ground-level ozone |
| 8 | (2021 page) | 150 | Unhealthy for Sensitive Groups | PM2.5 — fine particulate matter (PM2.5), in wildfire smoke season |
| 9 | (2019 page) | 150 | Unhealthy for Sensitive Groups | O3 — ground-level ozone, in peak ozone season |
| 10 | (2019 page) | 147 | Unhealthy for Sensitive Groups | O3 — ground-level ozone |
Worst day of each year in Atlanta
The single highest-AQI day in each year on record. Click a year for its full month-by-month statistics.
| Year | Worst day | AQI | Category | Defining pollutant |
|---|---|---|---|---|
| 2019 | 172 | Unhealthy | O3 — ground-level ozone | |
| 2020 | 125 | Unhealthy for Sensitive Groups | PM2.5 — fine particulate matter (PM2.5), in wildfire smoke season | |
| 2021 | 150 | Unhealthy for Sensitive Groups | PM2.5 — fine particulate matter (PM2.5), in wildfire smoke season | |
| 2022 | 169 | Unhealthy | O3 — ground-level ozone, in peak ozone season | |
| 2023 | 172 | Unhealthy | O3 — ground-level ozone, in peak ozone season | |
| 2024 | 161 | Unhealthy | O3 — ground-level ozone, in peak ozone season | |
| 2025 | 129 | Unhealthy for Sensitive Groups | O3 — ground-level ozone, in peak ozone season |
Atlanta's 10 best air quality days, 2019–2025
Lowest daily AQI recorded for the Atlanta-Sandy Springs-Roswell, GA area. Ties are listed most recent first.
| # | Date | AQI | Category | Defining pollutant |
|---|---|---|---|---|
| 1 | (2021 page) | 20 | Good | NO2 — nitrogen dioxide |
| 2 | (2025 page) | 21 | Good | O3 — ground-level ozone |
| 3 | (2025 page) | 21 | Good | O3 — ground-level ozone |
| 4 | (2021 page) | 21 | Good | PM2.5 — fine particulate matter (PM2.5) |
| 5 | (2022 page) | 22 | Good | NO2 — nitrogen dioxide |
| 6 | (2023 page) | 23 | Good | O3 — ground-level ozone |
| 7 | (2020 page) | 23 | Good | O3 — ground-level ozone |
| 8 | (2020 page) | 23 | Good | O3 — ground-level ozone |
| 9 | (2019 page) | 23 | Good | PM2.5 — fine particulate matter (PM2.5) |
| 10 | (2024 page) | 24 | Good | O3 — ground-level ozone |
Right now in Atlanta
The latest EPA AirNow observation puts Atlanta's AQI at 59 (PM2.5). The days above are historical records, not today's reading.
View current Atlanta air quality →Source: EPA Air Quality System (AQS) pre-generated Daily AQI by CBSA files — daily AQI by CBSA (Atlanta-Sandy Springs-Roswell, GA), 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.