State air quality · 2025
Arkansas Air Quality Ranking
Across 11 monitored counties, the typical county in Arkansas posts a median AQI of 45 (Good) and 71.2% of monitored days were rated Good, from EPA AQS.
- 45
- Avg median AQI
- 71.2%
- Good-air days
- 11
- Counties monitored
- 21%
- Cleaner than US states
Arkansas's typical county median AQI is 45 (Good) across 11 monitored counties
According to the U.S. EPA Air Quality System, Arkansas monitors 11 counties with a day-weighted Good-day share of 71.2%. Cleanest: Clark County (96.7% Good). Most polluted: Pulaski County (31.2%). These are annual summaries, not live AirNow readings.
Data source EPA Air Quality System (AQS)
- Cleaner than US states
- Arkansas's day-weighted Good-day share of 71.2% places it cleaner than 21% of US states.
- In-state spread
- Within Arkansas, Clark County leads at 96.7% Good days while Pulaski County sits at 31.2% across 11 monitored counties.
- 2024→2025 release
- Arkansas's Good-day share moved -1.9 points vs the 2024 EPA annual release.
- Typical median AQI
- Typical median AQI: 45
Verify with AirNow → · EPA AQS →
EPA state monitoring brief
AQS state key ARKANSAS
Arkansas · 2025 EPA AQS · 11 counties · med AQI 45 · 71.2% Good · Clark→Pulaski spread
- GOOD 45 Median AQI · Good
- SHARE 71.2% Good-day share
- COUNT 11 Counties monitored
- UNH 0 Unhealthy+ days
- RANK 21% Cleaner than states
- O3 57.6% Main pollutant share
Good-day share peers
Arkansas's 71.2% Good-day share is cleaner than 21% of monitored US states; Clark and Pulaski County bracket the in-state range. Open Clark County →
According to EPA AQS annual summaries on PlainAirData, Arkansas ranks #41 of 52 by day-weighted good-day share (71.2%) and #49 by mean county median AQI (44.7). 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
71.2%
Good-day share in 2025, down 1.9 percentage points vs 2024. County-mean median AQI 45, 1.6 points higher (worse) than 2024.
Pollutant mix
Ozone
Main driver on 57.6% of pollutant-assigned days.
- Ozone 57.6%
- PM2.5 42.2%
- NO2 0.3%
Monitoring coverage
248
Average monitored days per county in the latest release. Every monitored county clears the 100-day ranking floor.
Counties Monitored
11
Good Days %
71.2%
Avg Median AQI
45
Total Unhealthy Days
0
Best Air Quality
Clark County
Worst Air Quality
Pulaski County
Where Arkansas sits nationally
COUNT-derived placement among 52 US states with at least 365 monitored days in the latest county release. Arkansas's day-weighted Good-day share is 71.2% - cleaner than 21% of that comparison set.
Arkansas Good-day share vs. every US state
Day-weighted share of monitored days in the Good band (AQI 0–50) - EPA AQS annual release
71.2% 21st percentile higher than 21% of 52 US states
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 Arkansas have the cleanest and most polluted air?
Cleanest counties in Arkansas
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: 11 counties in Arkansas 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.