EnviroNearby

Perry County, Missouri air quality history

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

85%
Good days in 2025
41
Median daily AQI, 2025
1
Days above 100 in 2025
255
Days with an AQI in 2025 (of 365)

In 2025, EPA reported a daily Air Quality Index (AQI) for Perry, Missouri on 255 days. 216 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 255 days. Across the years with fuller monitoring, the share of Good days rose: an average of 64% in 2004–2006 versus 82% in 2023–2025.

EPA did not report an AQI for every day of 2025 here (255 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 164 of 214 days2004: Moderate 49 of 214 days2004: Unhealthy for Sensitive Groups 1 of 214 days20042005: Good 116 of 214 days2005: Moderate 76 of 214 days2005: Unhealthy for Sensitive Groups 20 of 214 days2005: Unhealthy 2 of 214 days2006: Good 134 of 214 days2006: Moderate 68 of 214 days2006: Unhealthy for Sensitive Groups 12 of 214 days20062007: Good 118 of 214 days2007: Moderate 70 of 214 days2007: Unhealthy for Sensitive Groups 24 of 214 days2007: Unhealthy 2 of 214 days2008: Good 131 of 214 days2008: Moderate 80 of 214 days2008: Unhealthy for Sensitive Groups 3 of 214 days20082009: Good 160 of 211 days2009: Moderate 47 of 211 days2009: Unhealthy for Sensitive Groups 4 of 211 days2010: Good 131 of 214 days2010: Moderate 76 of 214 days2010: Unhealthy for Sensitive Groups 7 of 214 days20102011: Good 166 of 243 days2011: Moderate 70 of 243 days2011: Unhealthy for Sensitive Groups 7 of 243 days2012: Good 124 of 214 days2012: Moderate 65 of 214 days2012: Unhealthy for Sensitive Groups 24 of 214 days2012: Unhealthy 1 of 214 days20122013: Good 178 of 214 days2013: Moderate 36 of 214 days2014: Good 176 of 214 days2014: Moderate 38 of 214 days20142015: Good 178 of 214 days2015: Moderate 35 of 214 days2015: Unhealthy for Sensitive Groups 1 of 214 days2016: Good 173 of 214 days2016: Moderate 40 of 214 days2016: Unhealthy for Sensitive Groups 1 of 214 days20162017: Good 202 of 245 days2017: Moderate 43 of 245 days2018: Good 208 of 245 days2018: Moderate 36 of 245 days2018: Unhealthy for Sensitive Groups 1 of 245 days20182019: Good 224 of 245 days2019: Moderate 21 of 245 days2020: Good 231 of 245 days2020: Moderate 14 of 245 days20202021: Good 213 of 244 days2021: Moderate 29 of 244 days2021: Unhealthy for Sensitive Groups 2 of 244 days2022: Good 211 of 245 days2022: Moderate 34 of 245 days20222023: Good 179 of 245 days2023: Moderate 55 of 245 days2023: Unhealthy for Sensitive Groups 11 of 245 days2024: Good 218 of 251 days2024: Moderate 33 of 251 days20242025: Good 216 of 255 days2025: Moderate 38 of 255 days2025: Unhealthy for Sensitive Groups 1 of 255 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 712005: 90th percentile AQI 1012006: 90th percentile AQI 932007: 90th percentile AQI 1122008: 90th percentile AQI 772009: 90th percentile AQI 672010: 90th percentile AQI 842011: 90th percentile AQI 872012: 90th percentile AQI 1052013: 90th percentile AQI 582014: 90th percentile AQI 612015: 90th percentile AQI 612016: 90th percentile AQI 642017: 90th percentile AQI 612018: 90th percentile AQI 612019: 90th percentile AQI 502020: 90th percentile AQI 472021: 90th percentile AQI 512022: 90th percentile AQI 582023: 90th percentile AQI 742024: 90th percentile AQI 542025: 90th percentile AQI 542004: Median AQI 432005: Median AQI 492006: Median AQI 462007: Median AQI 482008: Median AQI 462009: Median AQI 442010: Median AQI 472011: Median AQI 462012: Median AQI 482013: Median AQI 422014: Median AQI 402015: Median AQI 412016: Median AQI 422017: Median AQI 442018: Median AQI 392019: Median AQI 402020: Median AQI 362021: Median AQI 392022: Median AQI 422023: Median AQI 442024: Median AQI 422025: 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
Ozone255100%

Year-by-year data

Annual AQI summary by year
YearDays with AQIGoodModerateUnhealthy for Sensitive GroupsUnhealthyVery UnhealthyHazardousMedian AQI90th pct.Max AQIMain pollutant
20252552163810004154105Ozone
2024251218330000425493Ozone
202324517955110004474150Ozone
2022245211340000425897Ozone
20212442132920003951122Ozone
2020245231140000364797Ozone
2019245224210000405087Ozone
20182452083610003961126Ozone
20172452024300004461100Ozone
20162141734010004264119Ozone
20152141783510004161129Ozone
2014214176380000406197Ozone
20132141783600004258100Ozone
2012214124652410048105159Ozone
20112431667070004687129Ozone
20102141317670004784133Ozone
20092111604740004467119Ozone
20082141318030004677112Ozone
2007214118702420048112169Ozone
200621413468120004693150Ozone
2005214116762020049101169Ozone
20042141644910004371112Ozone

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