State air quality · 2025

Tennessee Air Quality Ranking

Across 23 monitored counties, the typical county in Tennessee posts a median AQI of 38 (Good) and 80.3% of monitored days were rated Good, from EPA AQS.

38
Avg median AQI
80.3%
Good-air days
23
Counties monitored
63%
Cleaner than US states

Tennessee's typical county median AQI is 38 (Good) across 23 monitored counties

According to the U.S. EPA Air Quality System, Tennessee monitors 23 counties with a day-weighted Good-day share of 80.3%. Cleanest: Claiborne County (97.3% Good). Most polluted: Davidson County (52.9%). These are annual summaries, not live AirNow readings.

Data source EPA Air Quality System (AQS)

Cleaner than US states
Tennessee's day-weighted Good-day share of 80.3% places it cleaner than 63% of US states.
In-state spread
Within Tennessee, Claiborne County leads at 97.3% Good days while Davidson County sits at 52.9% across 23 monitored counties.
2024→2025 release
Tennessee's Good-day share moved +5.3 points vs the 2024 EPA annual release.
Typical median AQI
Typical median AQI: 38

Verify with AirNow → · EPA AQS →

EPA state monitoring brief

AQS state key TENNESSEE

Tennessee · 2025 EPA AQS · 23 counties · med AQI 38 · 80.3% Good · Claiborne→Davidson spread

  • GOOD 38 Median AQI · Good
  • SHARE 80.3% Good-day share
  • COUNT 23 Counties monitored
  • UNH 1 Unhealthy+ days
  • RANK 63% Cleaner than states
  • PM25 57.6% Main pollutant share

Good-day share peers

North Carolina81%South Dakota80.8%Kentucky80.6%Tennessee (this)80.3%
Good-day share neighbourhood · nearest ABS peers vs Tennessee

Tennessee's 80.3% Good-day share is cleaner than 63% of monitored US states; Claiborne and Davidson County bracket the in-state range. Open Claiborne County →

According to EPA AQS annual summaries on PlainAirData, Tennessee ranks #19 of 52 by day-weighted good-day share (80.3%) and #21 by mean county median AQI (38.4). Hawaii is #1 of 52 by day-weighted good-day share (93.8% of monitored days) at mean county median-AQI #4 (27.3) ≠ Alaska #1 lowest mean county median AQI (20.3) at good-day share #8 (84.4%).

Data updated August 2026

What changed, what drives it, and how thick is the sample

Three derived views WPR-style word count does not substitute for: release-over-release movement from county annual rows, the EPA main-pollutant day mix, and how many counties sit below the 100-day ranking floor.

Release change

80.3%

Good-day share in 2025, up 5.3 percentage points vs 2024. County-mean median AQI 38, 1.8 points lower (cleaner) than 2024.

Pollutant mix

PM2.5

Main driver on 57.6% of pollutant-assigned days.

  • PM2.5 57.6%
  • Ozone 42.3%
  • NO2 0.1%

Monitoring coverage

340

Average monitored days per county in the latest release. Every monitored county clears the 100-day ranking floor.

Counties Monitored

23

Good Days %

80.3%

Avg Median AQI

38

Total Unhealthy Days

1

Best Air Quality

Claiborne County

Worst Air Quality

Davidson County

Where Tennessee sits nationally

COUNT-derived placement among 52 US states with at least 365 monitored days in the latest county release. Tennessee's day-weighted Good-day share is 80.3% - cleaner than 63% of that comparison set.

Tennessee Good-day share vs. every US state

Day-weighted share of monitored days in the Good band (AQI 0–50) - EPA AQS annual release

80.3% Cleaner than 63% higher than 63% of 52 US states

0.0%–5.0%: 0 US states (0%). Below this entry. 5.0%–10.0%: 0 US states (0%). Below this entry. 10.0%–15.0%: 0 US states (0%). Below this entry. 15.0%–20.0%: 0 US states (0%). Below this entry. 20.0%–25.0%: 0 US states (0%). Below this entry. 25.0%–30.0%: 0 US states (0%). Below this entry. 30.0%–35.0%: 0 US states (0%). Below this entry. 35.0%–40.0%: 0 US states (0%). Below this entry. 40.0%–45.0%: 0 US states (0%). Below this entry. 45.0%–50.0%: 0 US states (0%). Below this entry. 50.0%–55.0%: 0 US states (0%). Below this entry. 55.0%–60.0%: 0 US states (0%). Below this entry. 60.0%–65.0%: 2 US states (4%). Below this entry. 65.0%–70.0%: 9 US states (17%). Below this entry. 70.0%–75.0%: 11 US states (21%). Below this entry. 75.0%–80.0%: 11 US states (21%). Below this entry. 80.0%–85.0%: 13 US states (25%). This entry sits in this band. 85.0%–90.0%: 5 US states (10%). Above this entry. 90.0%–95.0%: 1 US states (2%). Above this entry. 95.0%–100.0%: 0 US states (0%). Above this entry. 100.0%–105.0%: 0 US states (0%). Above this entry. This state 0.0% 100% every floor-qualified US state, bucketed by value

Each bar is a band; taller bars hold more US states. The dashed line + filled bar mark this entry. Hover or tap any bar for its full count, share, and where it sits relative to this entry.

Source U.S. Environmental Protection Agency, Air Quality System (AQS) · 2025

Which counties in Tennessee have the cleanest and most polluted air?

Cleanest counties in Tennessee

Share of monitored days rated Good (AQI 0–50)

  1. 1 Claiborne County 97.3%
  2. 2 Sevier County 96.7%
  3. 3 DeKalb County 96.6%
  4. 4 Anderson County 94.3%
  5. 5 Wilson County 93.4%
  6. 6 Jefferson County 90.7%
  7. 7 Putnam County 90%
  8. 8 Williamson County 88.9%
  9. 9 Roane County 88.6%
  10. 10 Loudon County 85.5%
  11. 11 Montgomery County 83.8%
  12. 12 Maury County 83.5%

Good-day share · EPA Air Quality System

County Good % Median AQI
Claiborne 97.3% 35
Sevier 96.7% 40
DeKalb 96.6% 34
Anderson 94.3% 39
Wilson 93.4% 38
Jefferson 90.7% 41
Putnam 90.0% 30
Williamson 88.9% 40
Roane 88.6% 29
Loudon 85.5% 39
Montgomery 83.8% 32
Maury 83.5% 33
Sullivan 82.0% 40
Lawrence 81.5% 33
McMinn 78.2% 37
Dyer 76.9% 34
Madison 74.3% 36
Blount 71.5% 44
Sumner 69.3% 44
Hamilton 64.9% 44
Knox 63.0% 46
Shelby 60.3% 47
Davidson 52.9% 49

Data Sources

Primary Source: U.S. Environmental Protection Agency (EPA), Air Quality System (AQS), Annual AQI by County dataset, 2020–2025. See our methodology for how AQI and median figures are computed.

Coverage: 23 counties in Tennessee with active monitoring stations. Unmonitored counties are not represented.

Source: U.S. EPA Air Quality System (AQS) Annual AQI by county summary files, aggregated to the state level · 2020–2025

Every figure on PlainAirData is rendered directly from EPA AQS air-quality monitoring data, no number is typed in by an editor. This page draws directly on EPA AQS air-quality monitoring data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.

Informational only, not professional advice. Data from EPA AQS. See our disclaimer.