Bad Air Days in Hancock County, Kentucky: 2 a Year

2 bad air days a year

Fewer bad air days than most monitored US counties. Ranked 574 of 996 monitored counties, where 1 is worst.

What makes them bad: mostly ozone: summer smog (0% particle days).

When the bad days come in Hancock

Most bad days here fall in June. Averaged over 2016 to 2025.

Is a purifier worth it here?

Bad air days are rare here. A standard furnace filter is enough; no purifier needed for outdoor air.
On the odd bad day, check AirNow and keep windows shut.

Better or worse than it was

In 2000 to 2009 this county averaged 22 bad days a year; in 2016 to 2025, 2. The air has improved. The worst recent year was 2023, with 6 bad days on 245 monitored days.

Date	AQI	Main pollutant
2023-06-24	140	Ozone
2016-06-25	126	Ozone
2023-06-28	126	Ozone
2016-06-16	119	Ozone
2023-06-06	112	Ozone

Most days, not the worst ones

Across 2,302 monitored days from 2016 to 2025, the air in Hancock County rated Good on 87% of them, more often than the 72% typical of monitored counties, and Moderate on 12%. The median day sat at AQI 40; one day in ten went above 54.

The pollutant setting the AQI on an ordinary day here:

ozone100%2,302 days

Year by year

Year	Days monitored	Good	Moderate	Over 100	Over 150	Median AQI	Highest AQI
2025*	242	200	42	0	0	43	97
2024	229	200	29	0	0	44	100
2023	245	201	38	6	0	42	140
2022	243	219	23	1	0	40	108
2021	241	220	21	0	0	38	90
2020	245	233	12	0	0	37	97
2019	245	208	37	0	0	42	84
2018	125	115	10	0	0	38	97
2017	245	217	28	0	0	40	90
2016	242	200	39	3	0	39	126
2015	245	203	37	5	0	41	115
2014	237	198	38	1	0	41	105
2013	237	209	27	1	0	40	110
2012	244	168	58	18	2	44	179
2011	236	172	56	8	0	44	129
2010	241	151	82	8	0	46	122

*2025 may be a partial year in EPA's file.

Nearby counties on file

How this is counted

A bad air day is a day the county's daily AQI from EPA AirData went above 100, the level where EPA tells children, older adults and people with asthma or heart disease to cut back outdoors. Monitors do not run every day, so yearly counts are scaled to 365 days. This is the record, not today's air: for that, check AirNow. More on the method in how the county numbers are made, on the AQI 100 line in what counts as a bad air day, and on why a purifier does not touch ozone in smoke vs ozone.