EnviroNearby

Brown County, Kansas air quality history

Daily Air Quality Index summaries from EPA monitors in Brown, Kansas, 2002–2011.

50%
Good days in 2005
51
Median daily AQI, 2005
1
Days above 100 in 2005
121
Days with an AQI in 2005 (of 365)

In 2005, EPA reported a daily Air Quality Index (AQI) for Brown, Kansas on 121 days. 60 of those days (50%) were in the Good range, and the median daily AQI was 51. That median is higher than the typical monitored county in Kansas (median 44 across 12 counties), and higher than the typical monitored U.S. county (44). The main pollutant was fine particles (PM2.5) on 121 days.

EPA did not report an AQI for every day of 2005 here (121 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.

The most recent year with data for this county is 2011; EPA's files for 2012–2025 contain no row for it, which usually means its monitors stopped reporting.

Years with fewer than 120 monitored days (2006, 2007, 2008, 2009, 2010, 2011…) are shown in the table but left out of comparisons and trend statements.

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%2002: Good 33 of 65 days2002: Moderate 31 of 65 days2002: Unhealthy for Sensitive Groups 1 of 65 days20022003: Good 64 of 114 days2003: Moderate 50 of 114 days20032004: Good 73 of 118 days2004: Moderate 45 of 118 days20042005: Good 60 of 121 days2005: Moderate 60 of 121 days2005: Unhealthy for Sensitive Groups 1 of 121 days20052006: Good 80 of 118 days2006: Moderate 38 of 118 days20062007: Good 73 of 113 days2007: Moderate 40 of 113 days20072008: Good 80 of 119 days2008: Moderate 39 of 119 days20082009: Good 83 of 113 days2009: Moderate 29 of 113 days2009: Unhealthy for Sensitive Groups 1 of 113 days20092010: Good 83 of 116 days2010: Moderate 33 of 116 days20102011: Good 33 of 54 days2011: Moderate 21 of 54 days2011
  • 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 year0501002002: 90th percentile AQI 662003: 90th percentile AQI 662004: 90th percentile AQI 632005: 90th percentile AQI 702006: 90th percentile AQI 602007: 90th percentile AQI 612008: 90th percentile AQI 582009: 90th percentile AQI 572010: 90th percentile AQI 622011: 90th percentile AQI 632002: Median AQI 502003: Median AQI 452004: Median AQI 432005: Median AQI 512006: Median AQI 392007: Median AQI 422008: Median AQI 412009: Median AQI 352010: Median AQI 382011: Median AQI 432002200320042005200620072008200920102011
  • Median daily AQI
  • 90th-percentile daily AQI

Main pollutant by day, 2005

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
Fine particles (PM2.5)121100%

Year-by-year data

Annual AQI summary by year
YearDays with AQIGoodModerateUnhealthy for Sensitive GroupsUnhealthyVery UnhealthyHazardousMedian AQI90th pct.Max AQIMain pollutant
20115433210000436399PM2.5
201011683330000386279PM2.5
2009113832910003557107PM2.5
200811980390000415877PM2.5
200711373400000426191PM2.5
200611880380000396077PM2.5
2005121606010005170102PM2.5
200411873450000436383PM2.5
200311464500000456696PM2.5
200265333110005066106PM2.5

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.

All monitored counties in Kansas

Source: U.S. EPA AirData, “Annual AQI by County” files for 2002–2011 (EPA download page). EPA file dates: 2026-06-26. Imported into EnviroNearby November 5, 2026. How we use this data · Report a problem