EnviroNearby

Franklin County, Kentucky air quality history

Daily Air Quality Index summaries from EPA monitors in Franklin, Kentucky, 1999–2011.

36%
Good days in 2010
55
Median daily AQI, 2010
0
Days above 100 in 2010
122
Days with an AQI in 2010 (of 365)

In 2010, EPA reported a daily Air Quality Index (AQI) for Franklin, Kentucky on 122 days. 44 of those days (36%) were in the Good range, and the median daily AQI was 55. That median is higher than the typical monitored county in Kentucky (median 47.5 across 30 counties), and higher than the typical monitored U.S. county (44). The main pollutant was fine particles (PM2.5) on 122 days.

EPA did not report an AQI for every day of 2010 here (122 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 2011; EPA's files for 2012–2025 contain no row for it, which usually means its monitors stopped reporting.

Years with fewer than 120 monitored days (2003, 2004, 2005, 2006, 2008, 2011…) 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%1999: Good 25 of 106 days1999: Moderate 81 of 106 days19992000: Good 22 of 115 days2000: Moderate 90 of 115 days2000: Unhealthy for Sensitive Groups 3 of 115 days20002001: Good 33 of 107 days2001: Moderate 71 of 107 days2001: Unhealthy for Sensitive Groups 3 of 107 days20012002: Good 32 of 111 days2002: Moderate 77 of 111 days2002: Unhealthy for Sensitive Groups 2 of 111 days20022003: Good 39 of 116 days2003: Moderate 76 of 116 days2003: Unhealthy for Sensitive Groups 1 of 116 days20032004: Good 40 of 115 days2004: Moderate 75 of 115 days20042005: Good 30 of 118 days2005: Moderate 84 of 118 days2005: Unhealthy for Sensitive Groups 4 of 118 days20052006: Good 48 of 118 days2006: Moderate 69 of 118 days2006: Unhealthy for Sensitive Groups 1 of 118 days20062007: Good 36 of 120 days2007: Moderate 82 of 120 days2007: Unhealthy for Sensitive Groups 2 of 120 days20072008: Good 44 of 119 days2008: Moderate 75 of 119 days20082009: Good 50 of 122 days2009: Moderate 72 of 122 days20092010: Good 44 of 122 days2010: Moderate 78 of 122 days20102011: Good 45 of 100 days2011: Moderate 55 of 100 days2011
  • 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 year0501001999: 90th percentile AQI 822000: 90th percentile AQI 792001: 90th percentile AQI 792002: 90th percentile AQI 792003: 90th percentile AQI 752004: 90th percentile AQI 702005: 90th percentile AQI 822006: 90th percentile AQI 752007: 90th percentile AQI 782008: 90th percentile AQI 692009: 90th percentile AQI 642010: 90th percentile AQI 672011: 90th percentile AQI 661999: Median AQI 572000: Median AQI 612001: Median AQI 572002: Median AQI 562003: Median AQI 552004: Median AQI 552005: Median AQI 562006: Median AQI 542007: Median AQI 552008: Median AQI 542009: Median AQI 522010: Median AQI 552011: Median AQI 531999200020012002200320042005200620072008200920102011
  • Median daily AQI
  • 90th-percentile daily AQI

Main pollutant by day, 2010

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
Fine particles (PM2.5)122100%

Year-by-year data

Annual AQI summary by year
YearDays with AQIGoodModerateUnhealthy for Sensitive GroupsUnhealthyVery UnhealthyHazardousMedian AQI90th pct.Max AQIMain pollutant
201110045550000536698PM2.5
201012244780000556783PM2.5
200912250720000526476PM2.5
200811944750000546986PM2.5
2007120368220005578122PM2.5
2006118486910005475105PM2.5
2005118308440005682134PM2.5
200411540750000557088PM2.5
2003116397610005575103PM2.5
2002111327720005679130PM2.5
2001107337130005779144PM2.5
2000115229030006179122PM2.5
1999106258100005782100PM2.5

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 Kentucky with a similar median AQI in 2010

All monitored counties in Kentucky

Source: U.S. EPA AirData, “Annual AQI by County” files for 1999–2011 (EPA download page). EPA file dates: 2026-06-26. Imported into EnviroNearby November 5, 2026. How we use this data · Report a problem