Median AQI
37
Good
Kansas · County air quality · 2025
Douglas County, Kansas
Median AQI 37 (Good). 92.9% of monitored days rated Good, direct from EPA Air Quality System stations.
- 37
- Median AQI
- 92.9%
- Good-air days
- 0
- Unhealthy days
- 87%
- Cleaner than US counties
Douglas County's 2025 annual median AQI is 37 (Good), with 92.9% Good days
According to the U.S. EPA Air Quality System, Douglas County, Kansas posted a 2025 median AQI of 37 (Good) across 283 monitored days, with 92.9% rated Good and 0 unhealthy or worse. This is an annual comparison, not today's advisory.
Data source EPA Air Quality System (AQS)
- Cleaner than US
- Douglas County's 92.9% Good-day share places it cleaner than 87% of US counties in 2025.
- Closest median-AQI peer
- Alachua County (88.7% Good, median AQI 37) is the closest nationwide median-AQI peer to Douglas County.
- Median AQI
- Median AQI: 37
- Good days
- Good days: 92.9%
The verdict
According to EPA Air Quality System monitoring data, Douglas County's air is good on balance, cleaner than most US counties, a median AQI of 37 with 92.9% of 283 monitored days in the Good band, driven mainly by Ozone.
- 37
- median AQI · Good
- 92.9%
- days rated Good
- Ozone
- main pollutant
- 87%
- cleaner than US counties
Not one day crossed into the Unhealthy tier; the worst single reading was AQI 101.
Data updated August 2026
- Good · 263 d · 92.9%
- Moderate · 19 d · 6.7%
- USG · 1 d · 0.4%
How did Douglas County's air break down in 2025?
Across 283 monitored days, 263 fell in the Good band (AQI 0–50) and 0 reached Unhealthy or worse. The worst single day peaked at AQI 101 (USG).
EPA AQS →Air quality data from EPA Air Quality System (2025). 283 days monitored. Median AQI: 37 (Good).
Insights: Douglas County, Kansas. EPA monitors recorded a median Air Quality Index of 37 across 283 measured days in 2025, earning a Good classification and a Excellent health grade. Of those days, 263 (93%) fell in the Good band (AQI 0–50), 19 (7%) registered Moderate readings, and 1 (0%) reached Unhealthy for Sensitive Groups. The 90th-percentile AQI settled at 49, while the worst single-day peak hit 101 (USG). Residents averaged about 27.9 clean-air days per 30-day window during the monitoring year.
The full pollutant mix ranks as Ozone (283 days). Across the 2025–2025 trend window, the share of monitored days rated Good shifted by an amount the record cannot support and the median AQI moved +0 points, placing the multi-year trajectory at tracked. The worst single reading over the 2025–2025 window was AQI 101, usg but never Unhealthy. Nearby counties show comparable readings: Chase (82.8% good, AQI 31); Ford (89.8% good, AQI 28); Johnson (68.5% good, AQI 44); Leavenworth (94.0% good, AQI 34); Neosho (64.1% good, AQI 44); Sedgwick (57.5% good, AQI 48).
Air Quality Summary
Good Days
92.9%
263 of 283 monitored days
17.9pp vs 75% target
Max AQI Recorded
101
USG
Health Grade
Excellent
90th-pct AQI 49
Douglas County, Good days share 92.9%
National avg
Share of monitored days at AQI 0-50 (Good band).
Douglas County, Unhealthy-or-worse share 0.0%
National avg
Share of monitored days above AQI 150 (Unhealthy or worse). Bar maxes at 10% (worst-county ceiling).
AQI Day Breakdown (2025)
Distribution of 283 monitored days across EPA AQI categories.
Good
263
93%
Moderate
19
7%
USG
1
0%
Unhealthy
0
0%
Very Unhealthy
0
0%
Hazardous
0
0%
Pollutant Breakdown
Days where each pollutant was the primary driver of AQI readings in Douglas County.
- Ozone · 283 days · 100.0%
Health Impact Assessment
Excellent
Douglas County's air quality is rated Excellent based on 92.9% good air days. No unhealthy air days were recorded in 2025.
Air quality was acceptable on 92.9% of monitored days in 2025, with a median AQI of 37. Unusually sensitive people can check real-time conditions at AirNow.gov during high-pollution events.
The dominant pollutant is Ozone, driving AQI on 283 of 283 monitored days.
How does Douglas County compare?
How Douglas County compares
Good-day share better than typical
Douglas County 92.9%
Alachua County, Florida 88.7%
Typical US county 76.0%
Median AQI better than typical
Douglas County 37
Alachua County, Florida 37
Typical US county 39
Unhealthy days / yr better than typical
Douglas County 0
Alachua County, Florida 0
Typical US county 1
Counties with a similar median AQI
Nationwide peers within about the same annual median AQI as Douglas County (37), not geographic neighbors.
Alachua County, Florida
Median AQI 37 · 88.7% Good-day share
Arlington County, Virginia
Median AQI 37 · 87.4% Good-day share
Bennington County, Vermont
Median AQI 37 · 83.6% Good-day share
Boone County, Missouri
Median AQI 37 · 93.2% Good-day share
Bradford County, Pennsylvania
Median AQI 37 · 81.6% Good-day share
Brown County, Wisconsin
Median AQI 37 · 73.2% Good-day share
Same primary pollutant: Ozone
Ozone led the AQI on the most monitored days here. These peers share that driver and the closest Good-day share (a second relationship type beyond median-AQI neighbors).
Niagara County, New York
92.9% Good-day share · median AQI 34
Johnson County, Wyoming
92.8% Good-day share · median AQI 41
Greenbrier County, West Virginia
93.0% Good-day share · median AQI 37
Kent County, Rhode Island
92.8% Good-day share · median AQI 31
Perry County, Indiana
92.7% Good-day share · median AQI 36
St. John the Baptist County, Louisiana
93.1% Good-day share · median AQI 34
Kansas counties on the map
Geographic containment only, other monitored counties in Kansas, independent of AQI or pollutant match.
What Douglas County's air means for you
The air here stays in the breathable range year-round, with Ozone the main thing to watch.
- Sensitive groups (asthma, heart conditions, children, older adults) should check the AQI on high-Ozone days, the guide explains what a median of 37 means for exposure. Health guidance
- See how Douglas County ranks against every monitored U.S. county on Good-day share. County rankings
- Compare Douglas County with its Kansas neighbours before drawing a conclusion about the region. All of Kansas
Based on 283 EPA-monitored days in 2025; figures reflect only days the monitors reported. Source: EPA Air Quality System annual summaries.
Keep exploring the annual AQI record
Air-quality reading list
Frequently Asked Questions
What is the air quality in Douglas County, Kansas? ▼
Douglas County has a median Air Quality Index (AQI) of 37, rated "Good." 92.9% of monitored days (263 out of 283) had good air quality in 2025.
What is the main pollutant in Douglas County? ▼
The primary pollutant in Douglas County is Ozone (O3), which was the main AQI driver on 283 days (100% of monitored days). Can trigger asthma, reduce lung function, and cause chest pain.
How many unhealthy air days does Douglas County have? ▼
In 2025, Douglas County recorded 0 unhealthy air days (0 Unhealthy, 0 Very Unhealthy, 0 Hazardous). The maximum AQI reached 101.
Is the air quality in Douglas County getting better or worse? ▼
Insufficient trend data is available for Douglas County.
What does AQI 37 mean for health? ▼
Douglas County's median AQI of 37 falls in the "Good" category. See the AQI category guide for what each range means for health.
How does Douglas County compare to other counties in Kansas? ▼
Douglas County has 92.9% good air days. Nearby counties in Kansas: Chase (82.8% good), Ford (89.8% good), Johnson (68.5% good), Leavenworth (94.0% good), Neosho (64.1% good), Sedgwick (57.5% good).
What is the 90th percentile AQI in Douglas County? ▼
The 90th percentile AQI for Douglas County is 49, meaning 90% of monitored days had an AQI at or below this level. The maximum AQI recorded was 101 (USG).
Data Sources
Primary Source: U.S. Environmental Protection Agency (EPA), Air Quality System (AQS), Annual AQI by County dataset, 2020–2025 (aqs.epa.gov). For current conditions (not shown here — this page is historical annual data), see EPA AirNow (airnow.gov). See our methodology for how AQI, median, and coverage figures are computed.
Informational only, not professional advice. Data from EPA AQS. See our disclaimer. Spotted a figure that looks wrong? Report a correction.
Source: U.S. EPA Air Quality System (AQS) Annual AQI by county summary files for Douglas County, Kansas · 2020–2025
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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.