State air quality · 2025

Kansas Air Quality Ranking

Across 12 monitored counties, the typical county in Kansas posts a median AQI of 39 (Good) and 74.7% of monitored days were rated Good, from EPA AQS.

39
Avg median AQI
74.7%
Good-air days
12
Counties monitored
38%
Cleaner than US states

Kansas's typical county median AQI is 39 (Good) across 12 monitored counties

According to the U.S. EPA Air Quality System, Kansas monitors 12 counties with a day-weighted Good-day share of 74.7%. Cleanest: Leavenworth County (94.0% Good). Most polluted: Sedgwick County (57.5%). These are annual summaries, not live AirNow readings.

Data source EPA Air Quality System (AQS)

Cleaner than US states
Kansas's day-weighted Good-day share of 74.7% places it cleaner than 38% of US states.
In-state spread
Within Kansas, Leavenworth County leads at 94.0% Good days while Sedgwick County sits at 57.5% across 12 monitored counties.
2024→2025 release
Kansas's Good-day share moved +0.6 points vs the 2024 EPA annual release.
Typical median AQI
Typical median AQI: 39

Verify with AirNow → · EPA AQS →

EPA state monitoring brief

AQS state key KANSAS

Kansas · 2025 EPA AQS · 12 counties · med AQI 39 · 74.7% Good · Leavenworth→Sedgwick spread

  • GOOD 39 Median AQI · Good
  • SHARE 74.7% Good-day share
  • COUNT 12 Counties monitored
  • UNH 10 Unhealthy+ days
  • RANK 38% Cleaner than states
  • PM25 49.6% Main pollutant share

Good-day share peers

Kansas (this)74.7%Michigan74.7%Louisiana74.6%Delaware74.1%
Good-day share neighbourhood · nearest ABS peers vs Kansas

Kansas's 74.7% Good-day share is cleaner than 38% of monitored US states; Leavenworth and Sedgwick County bracket the in-state range. Open Leavenworth County →

According to EPA AQS annual summaries on PlainAirData, Kansas ranks #31 of 52 by day-weighted good-day share (74.7%) and #26 by mean county median AQI (39.0). 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

74.7%

Good-day share in 2025, up 0.6 percentage points vs 2024. County-mean median AQI 39, within half a point of the 2024 county-mean median.

Pollutant mix

PM2.5

Main driver on 49.6% of pollutant-assigned days.

  • PM2.5 49.6%
  • Ozone 44.7%
  • PM10 5.5%
  • NO2 0.3%

Monitoring coverage

332

Average monitored days per county in the latest release. 1 of 12 counties sit below the 100-day floor used for cleanest/most-polluted claims.

Counties Monitored

12

Good Days %

74.7%

Avg Median AQI

39

Total Unhealthy Days

10

Best Air Quality

Leavenworth County

Worst Air Quality

Sedgwick County

Where Kansas sits nationally

COUNT-derived placement among 52 US states with at least 365 monitored days in the latest county release. Kansas's day-weighted Good-day share is 74.7% - cleaner than 38% of that comparison set.

Kansas Good-day share vs. every US state

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

74.7% 38th percentile higher than 38% 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%). This entry sits in this band. 75.0%–80.0%: 11 US states (21%). Above this entry. 80.0%–85.0%: 13 US states (25%). Above this entry. 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 Kansas have the cleanest and most polluted air?

Cleanest counties in Kansas

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

  1. 1 Leavenworth County 94%
  2. 2 Douglas County 92.9%
  3. 3 Sherman County 90.1%
  4. 4 Ford County 89.8%
  5. 5 Chase County 82.8%
  6. 6 Trego County 75.6%
  7. 7 Johnson County 68.5%
  8. 8 Sumner County 65.8%
  9. 9 Neosho County 64.1%
  10. 10 Shawnee County 64.1%
  11. 11 Wyandotte County 61.9%
  12. 12 Sedgwick County 57.5%

Good-day share · EPA Air Quality System

County Good % Median AQI
Leavenworth 94.0% 34
Douglas 92.9% 37
Sherman 90.1% 27
Ford 89.8% 28
Chase 82.8% 31
Trego 75.5% 41
Johnson 68.5% 44
Sumner 65.8% 45
Neosho 64.1% 44
Shawnee 64.1% 44
Wyandotte 61.9% 45
Sedgwick 57.5% 48

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: 12 counties in Kansas 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.