Knoxville Air Quality in 2021
In 2021, Knoxville's air quality (Knoxville, TN area) had a median daily AQI of 53 (Moderate) across 365 monitored days. 6 days (1.6%) reached Unhealthy for Sensitive Groups or worse, 146 were Good, and the year's peak AQI was 150 (Unhealthy for Sensitive Groups). Fine particulate matter (PM2.5) set the daily AQI on 274 of those days. The cleanest month of 2021 was January (median AQI 51, 0 days above 100) and the worst was July (median 59, 3 days above 100, peak 110).
- Good: 40.0%
- Moderate: 58.4%
- Unhealthy for Sensitive Groups: 1.6%
- Unhealthy or worse: 0.0%
Improve Indoor Air Quality
Even with good outdoor air in Knoxville, indoor PM2.5, dust and allergens build up. A True-HEPA purifier keeps a bedroom or office consistently clean.
Recommended: Levoit Core 400S — True HEPA · CADR ~141 CFM · rooms up to 219 sq ft
As an Amazon Associate, we earn from qualifying purchases.
How was Knoxville's air quality in 2021?
Moderate on a typical day: median AQI 53, with 6 days above AQI 100 out of 365 monitored — the 6th cleanest of 7 years on record for the area.
- ✓Peak AQI in 2021: 150 (Unhealthy for Sensitive Groups).
- ✓Fine particulate matter (PM2.5) was the main pollutant on 274 days.
- ✓Cleanest month: January; worst: July.
Frequently asked questions
What was the average AQI in Knoxville in 2021?▾
EPA's Air Quality System puts Knoxville's (Knoxville, TN) median daily AQI for 2021 at 53, which is Moderate. 6 days were Unhealthy for Sensitive Groups or worse and the year's highest AQI was 150.
Which month had the worst air quality in Knoxville in 2021?▾
The cleanest month of 2021 was January (median AQI 51, 0 days above 100) and the worst was July (median 59, 3 days above 100, peak 110).
Was 2021 a good or bad year for Knoxville's air?▾
Among the 7 years EPA has published for the area (2019–2025), 2021 ranks 6th cleanest by days above AQI 100. 2021's median of 53 is in line with the area's typical annual median of 52.
Knoxville month by month in 2021
Knoxville air quality month by month, 2021 (Knoxville, TN, EPA AQS daily AQI)
| Month | Days monitored | Median AQI | Days above 100 | Peak AQI | Main pollutant |
|---|---|---|---|---|---|
| Januarycleanest | 31 | 51 | 0 | 79 | PM2.5 |
| February | 28 | 52 | 0 | 63 | PM2.5 |
| March | 31 | 47 | 1 | 103 | PM2.5 |
| April | 30 | 54 | 1 | 150 | PM2.5 |
| May | 31 | 56 | 1 | 101 | O3 |
| June | 30 | 52 | 0 | 90 | PM2.5 |
| Julyworst | 31 | 59 | 3 | 110 | PM2.5 |
| August | 31 | 57 | 0 | 82 | PM2.5 |
| September | 30 | 53 | 0 | 73 | PM2.5 |
| October | 31 | 51 | 0 | 73 | PM2.5 |
| November | 30 | 54 | 0 | 70 | PM2.5 |
| December | 31 | 54 | 0 | 78 | PM2.5 |
How 2021 compares
Among the 7 years EPA has published for the area (2019–2025), 2021 ranks 6th cleanest by days above AQI 100.
2021's median of 53 is in line with the area's typical annual median of 52.
Activity-specific thresholds: running, cycling, kids' sports.
Right now in Knoxville
The latest EPA AirNow observation puts Knoxville's AQI at 50 (PM2.5). The figures above are multi-year annual statistics, not today's reading.
View current Knoxville air quality →Source: EPA Air Quality System (AQS) pre-generated Daily AQI by CBSA files — daily AQI by CBSA (Knoxville, 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.