EnviroNearby

Boyle County, Kentucky air quality history

Daily Air Quality Index summaries from EPA monitors in Boyle, Kentucky, 1980.

96%
Good days in 1980
19
Median daily AQI, 1980
1
Days above 100 in 1980
160
Days with an AQI in 1980 (of 366)

In 1980, EPA reported a daily Air Quality Index (AQI) for Boyle, Kentucky on 160 days. 153 of those days (96%) were in the Good range, and the median daily AQI was 19. That median is lower than the typical monitored county in Kentucky (median 39.5 across 18 counties), and lower than the typical monitored U.S. county (39). The main pollutant was ozone on 160 days.

EPA did not report an AQI for every day of 1980 here (160 of 366 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 1980; EPA's files for 1981–2025 contain no row for it, which usually means its monitors stopped reporting.

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%1980: Good 153 of 160 days1980: Moderate 6 of 160 days1980: Unhealthy for Sensitive Groups 1 of 160 days1980
  • 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 year0501001980: 90th percentile AQI 461980: Median AQI 191980
  • Median daily AQI
  • 90th-percentile daily AQI

Main pollutant by day, 1980

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
Ozone160100%

Year-by-year data

Annual AQI summary by year
YearDays with AQIGoodModerateUnhealthy for Sensitive GroupsUnhealthyVery UnhealthyHazardousMedian AQI90th pct.Max AQIMain pollutant
1980160153610001946119Ozone

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 Kentucky

Source: U.S. EPA AirData, “Annual AQI by County” files for 1980–1980 (EPA download page). EPA file dates: 2026-06-26. Imported into EnviroNearby November 5, 2026. How we use this data · Report a problem