Nashville Air Quality in September
Across 2019–2025, Nashville's September air quality had a median AQI of 53 (Moderate) over 210 monitored days in the Nashville-Davidson--Murfreesboro--Franklin, TN area. 0.0% of September days (0 of 210) reached Unhealthy for Sensitive Groups or worse, and fine particulate matter (PM2.5) set the daily AQI on 56.2% of days. The cleanest September on record here was 2024 (median AQI 44, 0 days above 100) and the worst was 2019 (median 61, 0 days above 100, peak AQI 93).
- Good: 41.4%
- Moderate: 58.6%
- Unhealthy for Sensitive Groups: 0.0%
- Unhealthy or worse: 0.0%
Reduce Indoor Ozone in Nashville
Today's main pollutant in Nashville is ground-level ozone (AQI 64). 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.
Recommended: Levoit Core 300 — True HEPA + activated carbon · CADR ~141 CFM · rooms up to 219 sq ft
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How is the air in Nashville in September?
Moderate on a typical day: median AQI 53 across 2019–2025, with 0.0% of September days above AQI 100. Fine particulate matter (PM2.5) is the main driver.
- ✓41.4% of September days were Good (AQI 0–50), 58.6% Moderate (51–100).
- ✓0 days of 210 reached AQI 101+; the September peak was 100.
- ✓Best September: 2024; worst September: 2019.
Frequently asked questions
What is the air quality like in Nashville in September?▾
Across 2019–2025, the median daily AQI in Nashville in September was 53 (Moderate). 41.4% of days were Good, 58.6% Moderate, and 0.0% reached Unhealthy for Sensitive Groups or worse, based on 210 monitored days in EPA's Air Quality System.
Is September a good time for outdoor exercise in Nashville?▾
A typical September day in Nashville is Moderate (median AQI 53): outdoor exercise is acceptable for most people, but unusually sensitive individuals should watch for symptoms, and fewer than 1% of September days reached AQI 101+ — the level at which EPA advises people with asthma, children and older adults to shorten hard outdoor exertion.
Which pollutant causes Nashville's September air quality problems?▾
Fine particulate matter (PM2.5) set the daily AQI on 56.2% of September days in Nashville. The highest September AQI recorded in 2019–2025 was 100 (Moderate), in 2019.
Nashville September air quality, year by year
Nashville September air quality by year (Nashville-Davidson--Murfreesboro--Franklin, TN, EPA AQS daily AQI)
| Year | Days monitored | Median AQI | Days above 100 | Peak AQI | Main pollutant |
|---|---|---|---|---|---|
| 2019worst | 30 | 61 | 0 | 93 | PM2.5 |
| 2020 | 30 | 48 | 0 | 77 | PM2.5 |
| 2021 | 30 | 54 | 0 | 69 | PM2.5 |
| 2022 | 30 | 46 | 0 | 87 | O3 |
| 2023 | 30 | 54 | 0 | 77 | PM2.5 |
| 2024cleanest | 30 | 44 | 0 | 80 | O3 |
| 2025 | 30 | 57 | 0 | 100 | O3 |
What September air means in Nashville
A typical September day in Nashville is Moderate (median AQI 53): outdoor exercise is acceptable for most people, but unusually sensitive individuals should watch for symptoms, and fewer than 1% of September days reached AQI 101+ — the level at which EPA advises people with asthma, children and older adults to shorten hard outdoor exertion.
September's median AQI of 53 is in line with Nashville's whole-year median of 52, so this period is neither a clean nor a dirty stretch for the area. Nationally, the median September AQI across every EPA metro area (100,699 metro-days, 2019–2025) is 43, so Nashville runs above the national September norm; 0.0% of its September days topped AQI 100 versus 2.7% nationally (below average).
September is part of Nashville's fall season (September, October, November); the fall page pools all three months.
Activity-specific thresholds: running, cycling, kids' sports.
Right now in Nashville
The latest EPA AirNow observation puts Nashville's AQI at 64 (O3). The figures above are multi-year month statistics, not today's reading.
View current Nashville air quality →Source: EPA Air Quality System (AQS) pre-generated Daily AQI by CBSA files — daily AQI by CBSA (Nashville-Davidson--Murfreesboro--Franklin, TN), 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.