EnviroNearby

Cooper County, Missouri air quality history

Daily Air Quality Index summaries from EPA monitors in Cooper, Missouri, 2002–2006.

43%
Good days in 2006
56
Median daily AQI, 2006
0
Days above 100 in 2006
28
Days with an AQI in 2006 (of 365)

In 2006, EPA reported a daily Air Quality Index (AQI) for Cooper, Missouri on 28 days. 12 of those days (43%) were in the Good range, and the median daily AQI was 56. That median is higher than the typical monitored county in Missouri (median 50 across 17 counties), and higher than the typical monitored U.S. county (44). The main pollutant was fine particles (PM2.5) on 28 days.

EPA did not report an AQI for every day of 2006 here (28 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 2006; EPA's files for 2007–2025 contain no row for it, which usually means its monitors stopped reporting.

Years with fewer than 120 monitored days (2002, 2003, 2004, 2005, 2006) 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 3 of 9 days2002: Moderate 6 of 9 days20022003: Good 16 of 51 days2003: Moderate 35 of 51 days20032004: Good 17 of 57 days2004: Moderate 40 of 57 days20042005: Good 23 of 61 days2005: Moderate 35 of 61 days2005: Unhealthy for Sensitive Groups 3 of 61 days20052006: Good 12 of 28 days2006: Moderate 16 of 28 days2006
  • 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 722003: 90th percentile AQI 762004: 90th percentile AQI 762005: 90th percentile AQI 792006: 90th percentile AQI 672002: Median AQI 542003: Median AQI 562004: Median AQI 532005: Median AQI 552006: Median AQI 5620022003200420052006
  • Median daily AQI
  • 90th-percentile daily AQI

Main pollutant by day, 2006

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)28100%

Year-by-year data

Annual AQI summary by year
YearDays with AQIGoodModerateUnhealthy for Sensitive GroupsUnhealthyVery UnhealthyHazardousMedian AQI90th pct.Max AQIMain pollutant
20062812160000566776PM2.5
200561233530005579112PM2.5
20045717400000537696PM2.5
20035116350000567689PM2.5
20029360000547272PM2.5

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 Missouri

Source: U.S. EPA AirData, “Annual AQI by County” files for 2002–2006 (EPA download page). EPA file dates: 2026-06-26. Imported into EnviroNearby November 5, 2026. How we use this data · Report a problem