EnviroNearby

Callaway County, Missouri air quality history

Daily Air Quality Index summaries from EPA monitors in Callaway, Missouri, 2009–2025.

90%
Good days in 2025
41
Median daily AQI, 2025
0
Days above 100 in 2025
260
Days with an AQI in 2025 (of 365)

In 2025, EPA reported a daily Air Quality Index (AQI) for Callaway, Missouri on 260 days. 233 of those days (90%) 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 260 days. Across the years with fuller monitoring, the share of Good days rose: an average of 85% in 2009–2011 versus 88% in 2023–2025.

EPA did not report an AQI for every day of 2025 here (260 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%2009: Good 194 of 213 days2009: Moderate 19 of 213 days20092010: Good 172 of 214 days2010: Moderate 41 of 214 days2010: Unhealthy for Sensitive Groups 1 of 214 days2011: Good 205 of 245 days2011: Moderate 40 of 245 days20112012: Good 139 of 214 days2012: Moderate 64 of 214 days2012: Unhealthy for Sensitive Groups 11 of 214 days2013: Good 188 of 214 days2013: Moderate 26 of 214 days20132014: Good 192 of 213 days2014: Moderate 21 of 213 days2015: Good 186 of 214 days2015: Moderate 28 of 214 days20152016: Good 200 of 214 days2016: Moderate 13 of 214 days2016: Unhealthy for Sensitive Groups 1 of 214 days2017: Good 225 of 243 days2017: Moderate 18 of 243 days20172018: Good 210 of 245 days2018: Moderate 35 of 245 days2019: Good 238 of 245 days2019: Moderate 7 of 245 days20192020: Good 234 of 245 days2020: Moderate 11 of 245 days2021: Good 229 of 245 days2021: Moderate 16 of 245 days20212022: Good 222 of 244 days2022: Moderate 22 of 244 days2023: Good 197 of 245 days2023: Moderate 43 of 245 days2023: Unhealthy for Sensitive Groups 5 of 245 days20232024: Good 253 of 266 days2024: Moderate 13 of 266 days2025: Good 233 of 260 days2025: Moderate 27 of 260 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 year0501002009: 90th percentile AQI 502010: 90th percentile AQI 612011: 90th percentile AQI 582012: 90th percentile AQI 872013: 90th percentile AQI 512014: 90th percentile AQI 502015: 90th percentile AQI 512016: 90th percentile AQI 492017: 90th percentile AQI 492018: 90th percentile AQI 582019: 90th percentile AQI 472020: 90th percentile AQI 452021: 90th percentile AQI 472022: 90th percentile AQI 502023: 90th percentile AQI 642024: 90th percentile AQI 492025: 90th percentile AQI 512009: Median AQI 382010: Median AQI 422011: Median AQI 432012: Median AQI 452013: Median AQI 412014: Median AQI 392015: Median AQI 412016: Median AQI 382017: Median AQI 402018: Median AQI 402019: Median AQI 392020: Median AQI 352021: Median AQI 392022: Median AQI 402023: Median AQI 432024: Median AQI 402025: Median AQI 41200920112013201520172019202120232025
  • 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
Ozone260100%

Year-by-year data

Annual AQI summary by year
YearDays with AQIGoodModerateUnhealthy for Sensitive GroupsUnhealthyVery UnhealthyHazardousMedian AQI90th pct.Max AQIMain pollutant
2025260233270000415177Ozone
2024266253130000404977Ozone
20232451974350004364133Ozone
2022244222220000405074Ozone
2021245229160000394780Ozone
2020245234110000354587Ozone
201924523870000394771Ozone
2018245210350000405890Ozone
2017243225180000404967Ozone
20162142001310003849101Ozone
2015214186280000415197Ozone
2014213192210000395090Ozone
2013214188260000415177Ozone
201221413964110004587143Ozone
20112452054000004358100Ozone
20102141724110004261119Ozone
2009213194190000385077Ozone

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 2009–2025 (EPA download page). EPA file dates: 2026-06-26. Imported into EnviroNearby November 5, 2026. How we use this data · Report a problem