EnviroNearby

Clinton County, Missouri air quality history

Daily Air Quality Index summaries from EPA monitors in Clinton, Missouri, 2004–2025.

85%
Good days in 2025
41
Median daily AQI, 2025
3
Days above 100 in 2025
247
Days with an AQI in 2025 (of 365)

In 2025, EPA reported a daily Air Quality Index (AQI) for Clinton, Missouri on 247 days. 209 of those days (85%) were in the Good range, and the median daily AQI was 41. That median is about the same as the typical monitored county in Missouri (median 41 across 19 counties), and about the same as the typical monitored U.S. county (40). The main pollutant was ozone on 247 days. Across the years with fuller monitoring, the share of Good days rose: an average of 68% in 2004–2006 versus 80% in 2023–2025.

EPA did not report an AQI for every day of 2025 here (247 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%2004: Good 168 of 213 days2004: Moderate 40 of 213 days2004: Unhealthy for Sensitive Groups 5 of 213 days20042005: Good 129 of 214 days2005: Moderate 53 of 214 days2005: Unhealthy for Sensitive Groups 28 of 214 days2005: Unhealthy 4 of 214 days2006: Good 139 of 214 days2006: Moderate 52 of 214 days2006: Unhealthy for Sensitive Groups 20 of 214 days2006: Unhealthy 3 of 214 days20062007: Good 137 of 214 days2007: Moderate 58 of 214 days2007: Unhealthy for Sensitive Groups 16 of 214 days2007: Unhealthy 3 of 214 days2008: Good 174 of 214 days2008: Moderate 37 of 214 days2008: Unhealthy for Sensitive Groups 3 of 214 days20082009: Good 173 of 214 days2009: Moderate 37 of 214 days2009: Unhealthy for Sensitive Groups 4 of 214 days2010: Good 153 of 214 days2010: Moderate 49 of 214 days2010: Unhealthy for Sensitive Groups 12 of 214 days20102011: Good 174 of 245 days2011: Moderate 52 of 245 days2011: Unhealthy for Sensitive Groups 18 of 245 days2011: Unhealthy 1 of 245 days2012: Good 123 of 214 days2012: Moderate 64 of 214 days2012: Unhealthy for Sensitive Groups 24 of 214 days2012: Unhealthy 3 of 214 days20122013: Good 165 of 214 days2013: Moderate 45 of 214 days2013: Unhealthy for Sensitive Groups 4 of 214 days2014: Good 177 of 211 days2014: Moderate 34 of 211 days20142015: Good 167 of 214 days2015: Moderate 45 of 214 days2015: Unhealthy for Sensitive Groups 2 of 214 days2016: Good 176 of 214 days2016: Moderate 35 of 214 days2016: Unhealthy for Sensitive Groups 3 of 214 days20162017: Good 198 of 245 days2017: Moderate 47 of 245 days2018: Good 192 of 245 days2018: Moderate 51 of 245 days2018: Unhealthy for Sensitive Groups 2 of 245 days20182019: Good 213 of 245 days2019: Moderate 32 of 245 days2020: Good 226 of 245 days2020: Moderate 19 of 245 days20202021: Good 221 of 245 days2021: Moderate 24 of 245 days2022: Good 211 of 245 days2022: Moderate 33 of 245 days2022: Unhealthy for Sensitive Groups 1 of 245 days20222023: Good 168 of 245 days2023: Moderate 66 of 245 days2023: Unhealthy for Sensitive Groups 11 of 245 days2024: Good 224 of 262 days2024: Moderate 37 of 262 days2024: Unhealthy for Sensitive Groups 1 of 262 days20242025: Good 209 of 247 days2025: Moderate 35 of 247 days2025: Unhealthy for Sensitive Groups 3 of 247 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 year0501001502004: 90th percentile AQI 742005: 90th percentile AQI 1152006: 90th percentile AQI 1012007: 90th percentile AQI 932008: 90th percentile AQI 642009: 90th percentile AQI 642010: 90th percentile AQI 872011: 90th percentile AQI 842012: 90th percentile AQI 1052013: 90th percentile AQI 742014: 90th percentile AQI 582015: 90th percentile AQI 712016: 90th percentile AQI 672017: 90th percentile AQI 642018: 90th percentile AQI 712019: 90th percentile AQI 542020: 90th percentile AQI 482021: 90th percentile AQI 502022: 90th percentile AQI 582023: 90th percentile AQI 842024: 90th percentile AQI 582025: 90th percentile AQI 672004: Median AQI 432005: Median AQI 462006: Median AQI 452007: Median AQI 462008: Median AQI 432009: Median AQI 412010: Median AQI 442011: Median AQI 442012: Median AQI 492013: Median AQI 432014: Median AQI 402015: Median AQI 422016: Median AQI 422017: Median AQI 422018: Median AQI 422019: Median AQI 422020: Median AQI 372021: Median AQI 382022: Median AQI 412023: Median AQI 442024: Median AQI 412025: Median AQI 41200420062008201020122014201620182020202220242025
  • 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
Ozone247100%

Year-by-year data

Annual AQI summary by year
YearDays with AQIGoodModerateUnhealthy for Sensitive GroupsUnhealthyVery UnhealthyHazardousMedian AQI90th pct.Max AQIMain pollutant
20252472093530004167122Ozone
20242622243710004158101Ozone
202324516866110004484133Ozone
20222452113310004158101Ozone
2021245221240000385097Ozone
2020245226190000374887Ozone
2019245213320000425487Ozone
20182451925120004271143Ozone
2017245198470000426493Ozone
20162141763530004267129Ozone
20152141674520004271101Ozone
2014211177340000405893Ozone
20132141654540004374119Ozone
2012214123642430049105166Ozone
201124517452181004484159Ozone
201021415349120004487147Ozone
20092141733740004164133Ozone
20082141743730004364126Ozone
200721413758163004693161Ozone
2006214139522030045101159Ozone
2005214129532840046115169Ozone
20042131684050004374129Ozone

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 Missouri with a similar median AQI in 2025

All monitored counties in Missouri

Source: U.S. EPA AirData, “Annual AQI by County” files for 2004–2025 (EPA download page). EPA file dates: 2026-06-26. Imported into EnviroNearby November 5, 2026. How we use this data · Report a problem