EnviroNearby

Douglas County, Kansas air quality history

Daily Air Quality Index summaries from EPA monitors in Douglas, Kansas, 2003–2025.

93%
Good days in 2025
37
Median daily AQI, 2025
1
Days above 100 in 2025
283
Days with an AQI in 2025 (of 365)

In 2025, EPA reported a daily Air Quality Index (AQI) for Douglas, Kansas on 283 days. 263 of those days (93%) were in the Good range, and the median daily AQI was 37. That median is lower than the typical monitored county in Kansas (median 44 across 11 counties), and lower than the typical monitored U.S. county (40). The main pollutant was ozone on 283 days.

EPA did not report an AQI for every day of 2025 here (283 of 365 days). Figures describe monitored days only; seasonal monitoring (for example, ozone measured only in warmer months) can make a county look cleaner or dirtier than a full-year record would.

How the days broke down each year

Each bar is one year. The colored segments show the share of monitored days that fell in each AQI category.

Share of monitored days in each AQI category, by year0%25%50%75%100%2003: Good 186 of 261 days2003: Moderate 57 of 261 days2003: Unhealthy for Sensitive Groups 16 of 261 days2003: Unhealthy 2 of 261 days20032004: Good 333 of 362 days2004: Moderate 29 of 362 days20042005: Good 285 of 359 days2005: Moderate 64 of 359 days2005: Unhealthy for Sensitive Groups 9 of 359 days2005: Unhealthy 1 of 359 days20052006: Good 165 of 248 days2006: Moderate 65 of 248 days2006: Unhealthy for Sensitive Groups 18 of 248 days20062025: Good 263 of 283 days2025: Moderate 19 of 283 days2025: Unhealthy for Sensitive Groups 1 of 283 days2025
  • Good
  • Moderate
  • Unhealthy for Sensitive Groups
  • Unhealthy
  • Very Unhealthy
  • Hazardous

Typical and high-end AQI over time

The median is the middle day of the year. The 90th percentile is the level that only the highest 10% of days exceeded.

Median and 90th-percentile daily AQI, by year0501002003: 90th percentile AQI 842004: 90th percentile AQI 492005: 90th percentile AQI 742006: 90th percentile AQI 902025: 90th percentile AQI 492003: Median AQI 392004: Median AQI 352005: Median AQI 372006: Median AQI 442025: Median AQI 3720032004200520062025
  • Median daily AQI
  • 90th-percentile daily AQI

Main pollutant by day, 2025

On each monitored day, the AQI reflects whichever measured pollutant had the highest index. This counts how many days each pollutant set the AQI. A pollutant that was not measured here cannot appear.

PollutantDays as main pollutantShare of monitored days
Ozone283100%

Year-by-year data

Annual AQI summary by year
YearDays with AQIGoodModerateUnhealthy for Sensitive GroupsUnhealthyVery UnhealthyHazardousMedian AQI90th pct.Max AQIMain pollutant
20252832631910003749101Ozone
200624816565180004490150Ozone
20053592856491003774156Ozone
2004362333290000354997Ozone
200326118657162003984185Ozone

What this data can and can’t tell you

It is a county-level summary. EPA reports one AQI per day for the county, based on the monitors operating there. Air at a particular street, school or home can differ, especially near roads, industry or wildfire smoke.

It is not a health assessment. The AQI is EPA’s scale for communicating daily air quality. A county’s history can’t tell you what the health risk is for any particular person. For daily conditions and health guidance, see AirNow.

Rules change over time. EPA has revised AQI breakpoints, most recently for fine particles in 2024, so some year-to-year change can reflect the scale rather than the air.

Counties in Kansas with a similar median AQI in 2025

All monitored counties in Kansas

Source: U.S. EPA AirData, “Annual AQI by County” files for 2003–2025 (EPA download page). EPA file dates: 2026-06-26. Imported into EnviroNearby November 5, 2026. How we use this data · Report a problem