Knoxville Air Quality in December
Across 2019–2025, Knoxville's December air quality had a median AQI of 52 (Moderate) over 217 monitored days in the Knoxville, TN area. 0.0% of December days (0 of 217) reached Unhealthy for Sensitive Groups or worse, and fine particulate matter (PM2.5) set the daily AQI on 84.8% of days. The cleanest December on record here was 2024 (median AQI 46, 0 days above 100) and the worst was 2020 (median 57, 0 days above 100, peak AQI 74).
- Good: 45.6%
- Moderate: 54.4%
- Unhealthy for Sensitive Groups: 0.0%
- Unhealthy or worse: 0.0%
Extra Protection for Knoxville Homes
Air quality in Knoxville is moderate (AQI 61), 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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How is the air in Knoxville in December?
Moderate on a typical day: median AQI 52 across 2019–2025, with 0.0% of December days above AQI 100. Fine particulate matter (PM2.5) is the main driver.
- ✓45.6% of December days were Good (AQI 0–50), 54.4% Moderate (51–100).
- ✓0 days of 217 reached AQI 101+; the December peak was 78.
- ✓Best December: 2024; worst December: 2020.
Frequently asked questions
What is the air quality like in Knoxville in December?▾
Across 2019–2025, the median daily AQI in Knoxville in December was 52 (Moderate). 45.6% of days were Good, 54.4% Moderate, and 0.0% reached Unhealthy for Sensitive Groups or worse, based on 217 monitored days in EPA's Air Quality System.
Is December a good time for outdoor exercise in Knoxville?▾
A typical December day in Knoxville is Moderate (median AQI 52): outdoor exercise is acceptable for most people, but unusually sensitive individuals should watch for symptoms, and fewer than 1% of December 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 Knoxville's December air quality problems?▾
Fine particulate matter (PM2.5) set the daily AQI on 84.8% of December days in Knoxville. The highest December AQI recorded in 2019–2025 was 78 (Moderate), in 2020.
Knoxville December air quality, year by year
Knoxville December air quality by year (Knoxville, TN, EPA AQS daily AQI)
| Year | Days monitored | Median AQI | Days above 100 | Peak AQI | Main pollutant |
|---|---|---|---|---|---|
| 2019 | 31 | 48 | 0 | 68 | PM2.5 |
| 2020worst | 31 | 57 | 0 | 74 | PM2.5 |
| 2021 | 31 | 54 | 0 | 78 | PM2.5 |
| 2022 | 31 | 51 | 0 | 66 | PM2.5 |
| 2023 | 31 | 49 | 0 | 70 | PM2.5 |
| 2024cleanest | 31 | 46 | 0 | 74 | PM2.5 |
| 2025 | 31 | 49 | 0 | 66 | PM2.5 |
What December air means in Knoxville
A typical December day in Knoxville is Moderate (median AQI 52): outdoor exercise is acceptable for most people, but unusually sensitive individuals should watch for symptoms, and fewer than 1% of December days reached AQI 101+ — the level at which EPA advises people with asthma, children and older adults to shorten hard outdoor exertion.
December's median AQI of 52 is in line with Knoxville's whole-year median of 52, so this period is neither a clean nor a dirty stretch for the area. Nationally, the median December AQI across every EPA metro area (95,590 metro-days, 2019–2025) is 39, so Knoxville runs above the national December norm; 0.0% of its December days topped AQI 100 versus 0.7% nationally (about the same).
December is part of Knoxville's winter season (December, January, February); the winter page pools all three months.
Activity-specific thresholds: running, cycling, kids' sports.
Right now in Knoxville
The latest EPA AirNow observation puts Knoxville's AQI at 61 (PM2.5). The figures above are multi-year month 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.