Madison County, Kentucky air quality history

Daily Air Quality Index summaries from EPA monitors in Madison, Kentucky, 1988–2017.

41%

Good days in 2006

Median daily AQI, 2006

Days above 100 in 2006

125

Days with an AQI in 2006 (of 365)

In 2006, EPA reported a daily Air Quality Index (AQI) for Madison, Kentucky on 125 days. 51 of those days (41%) were in the Good range, and the median daily AQI was 54. That median is higher than the typical monitored county in Kentucky (median 44 across 29 counties), and higher than the typical monitored U.S. county (44). The main pollutant was fine particles (PM2.5) on 118 days.

EPA did not report an AQI for every day of 2006 here (125 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 2017; EPA's files for 2018–2025 contain no row for it, which usually means its monitors stopped reporting.

Years with fewer than 120 monitored days (2012, 2013, 2014, 2015, 2016, 2017…) 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.

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 daily AQI
90th-percentile daily AQI

Main pollutant by day, 2006

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.

Pollutant	Days as main pollutant	Share of monitored days
Fine particles (PM2.5)	118	94%
Coarse particles (PM10)	7	6%

Year-by-year data

Annual AQI summary by year
Year	Days with AQI	Good	Moderate	Unhealthy for Sensitive Groups	Unhealthy	Median AQI	90th pct.	Max AQI	Main pollutant
2017	113	84	29	0	0	39	56	73	PM2.5
2016	97	68	29	0	0	39	57	91	PM2.5
2015	112	80	32	0	0	39	58	74	PM2.5
2014	110	66	44	0	0	44	61	76	PM2.5
2013	114	74	40	0	0	44	58	72	PM2.5
2012	119	64	55	0	0	43	59	71	PM2.5
2011	117	67	50	0	0	47	63	77	PM2.5
2010	115	40	75	0	0	53	65	85	PM2.5
2009	116	48	68	0	0	52	63	69	PM2.5
2008	119	60	59	0	0	50	69	81	PM2.5
2007	118	42	74	2	0	56	79	124	PM2.5
2006	125	51	74	0	0	54	74	94	PM2.5
2005	124	36	87	1	0	58	80	118	PM2.5
2004	120	43	77	0	0	56	72	97	PM2.5
2003	116	35	81	0	0	54	77	92	PM2.5
2002	115	34	80	1	0	56	72	136	PM2.5
2001	113	34	78	1	0	56	78	138	PM2.5
2000	120	22	96	1	1	61	75	158	PM2.5
1999	107	29	78	0	0	58	82	98	PM2.5
1998	57	56	1	0	0	20	37	55	PM10
1997	60	60	0	0	0	20	35	50	PM10
1996	60	59	1	0	0	22	41	51	PM10
1995	60	57	3	0	0	23	45	58	PM10
1994	57	56	1	0	0	24	42	73	PM10
1993	60	59	1	0	0	19	40	52	PM10
1992	61	58	3	0	0	23	39	60	PM10
1991	57	56	1	0	0	26	43	56	PM10
1990	60	58	2	0	0	21	43	56	PM10
1989	60	56	4	0	0	24	48	70	PM10
1988	7	7	0	0	0	15	27	27	PM10

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 1988–2017 (EPA download page). EPA file dates: 2026-06-26. Imported into EnviroNearby November 5, 2026. How we use this data · Report a problem