EnviroNearby

McLean County, Kentucky air quality history

Daily Air Quality Index summaries from EPA monitors in McLean, Kentucky, 1991–2005.

62%
Good days in 2005
46
Median daily AQI, 2005
16
Days above 100 in 2005
239
Days with an AQI in 2005 (of 365)

In 2005, EPA reported a daily Air Quality Index (AQI) for McLean, Kentucky on 239 days. 148 of those days (62%) were in the Good range, and the median daily AQI was 46. That median is about the same as the typical monitored county in Kentucky (median 47 across 31 counties), and about the same as the typical monitored U.S. county (44). The main pollutant was ozone on 239 days. Across the years with fuller monitoring, the share of Good days rose: an average of 64% in 1992–1994 versus 67% in 2003–2005.

EPA did not report an AQI for every day of 2005 here (239 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 2005; EPA's files for 2006–2025 contain no row for it, which usually means its monitors stopped reporting.

Years with fewer than 120 monitored days (1991) 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%1991: Good 61 of 85 days1991: Moderate 20 of 85 days1991: Unhealthy for Sensitive Groups 3 of 85 days1991: Unhealthy 1 of 85 days19911992: Good 140 of 207 days1992: Moderate 53 of 207 days1992: Unhealthy for Sensitive Groups 14 of 207 days1993: Good 132 of 198 days1993: Moderate 52 of 198 days1993: Unhealthy for Sensitive Groups 12 of 198 days1993: Unhealthy 2 of 198 days19931994: Good 121 of 214 days1994: Moderate 50 of 214 days1994: Unhealthy for Sensitive Groups 30 of 214 days1994: Unhealthy 12 of 214 days1994: Very Unhealthy 1 of 214 days1995: Good 111 of 208 days1995: Moderate 69 of 208 days1995: Unhealthy for Sensitive Groups 24 of 208 days1995: Unhealthy 4 of 208 days19951996: Good 130 of 206 days1996: Moderate 59 of 206 days1996: Unhealthy for Sensitive Groups 17 of 206 days1997: Good 136 of 211 days1997: Moderate 59 of 211 days1997: Unhealthy for Sensitive Groups 15 of 211 days1997: Unhealthy 1 of 211 days19971998: Good 101 of 210 days1998: Moderate 76 of 210 days1998: Unhealthy for Sensitive Groups 30 of 210 days1998: Unhealthy 3 of 210 days1999: Good 100 of 207 days1999: Moderate 59 of 207 days1999: Unhealthy for Sensitive Groups 35 of 207 days1999: Unhealthy 11 of 207 days1999: Very Unhealthy 2 of 207 days19992000: Good 159 of 236 days2000: Moderate 66 of 236 days2000: Unhealthy for Sensitive Groups 11 of 236 days2001: Good 145 of 237 days2001: Moderate 72 of 237 days2001: Unhealthy for Sensitive Groups 19 of 237 days2001: Unhealthy 1 of 237 days20012002: Good 143 of 227 days2002: Moderate 48 of 227 days2002: Unhealthy for Sensitive Groups 23 of 227 days2002: Unhealthy 13 of 227 days2003: Good 151 of 242 days2003: Moderate 76 of 242 days2003: Unhealthy for Sensitive Groups 14 of 242 days2003: Unhealthy 1 of 242 days20032004: Good 180 of 237 days2004: Moderate 53 of 237 days2004: Unhealthy for Sensitive Groups 4 of 237 days2005: Good 148 of 239 days2005: Moderate 75 of 239 days2005: Unhealthy for Sensitive Groups 16 of 239 days2005
  • 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 year0501001501991: 90th percentile AQI 971992: 90th percentile AQI 871993: 90th percentile AQI 971994: 90th percentile AQI 1191995: 90th percentile AQI 1051996: 90th percentile AQI 971997: 90th percentile AQI 931998: 90th percentile AQI 1121999: 90th percentile AQI 1362000: 90th percentile AQI 842001: 90th percentile AQI 1002002: 90th percentile AQI 1192003: 90th percentile AQI 902004: 90th percentile AQI 712005: 90th percentile AQI 931991: Median AQI 431992: Median AQI 441993: Median AQI 451994: Median AQI 481995: Median AQI 501996: Median AQI 451997: Median AQI 421998: Median AQI 511999: Median AQI 542000: Median AQI 442001: Median AQI 452002: Median AQI 452003: Median AQI 452004: Median AQI 442005: Median AQI 4619911993199519971999200120032005
  • Median daily AQI
  • 90th-percentile daily AQI

Main pollutant by day, 2005

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
Ozone239100%

Year-by-year data

Annual AQI summary by year
YearDays with AQIGoodModerateUnhealthy for Sensitive GroupsUnhealthyVery UnhealthyHazardousMedian AQI90th pct.Max AQIMain pollutant
200523914875160004693133Ozone
20042371805340004471119Ozone
200324215176141004590154Ozone
20022271434823130045119179Ozone
2001237145721910045100166Ozone
200023615966110004484136Ozone
19992071005935112054136207Ozone
1998210101763030051112195Ozone
199721113659151004293161Ozone
199620613059170004597150Ozone
1995208111692440050105195Ozone
19942141215030121048119202Ozone
199319813252122004597151Ozone
199220714053140004487140Ozone
199185612031004397154Ozone

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 1991–2005 (EPA download page). EPA file dates: 2026-06-26. Imported into EnviroNearby November 5, 2026. How we use this data · Report a problem