Bad Air Days in Greenup County, Kentucky: under 1 a Year

under 1 bad air days a year

Rare: among the cleanest-air counties EPA monitors. Ranked 931 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 Greenup

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

What to buy, and what not to

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 21 bad days a year; in 2016 to 2025, under 1. The air has improved. The worst recent year was 2018, with 1 bad day on 238 monitored days.

Date	AQI	Main pollutant
2018-06-16	119	Ozone
2018-07-13	100	Ozone
2016-04-19	84	Ozone
2018-06-09	84	Ozone
2023-04-13	84	Ozone

Most days, not the worst ones

Across 2,371 monitored days from 2016 to 2025, the air in Greenup County rated Good on 95% of them, more often than the 72% typical of monitored counties, and Moderate on 5%. The median day sat at AQI 36; one day in ten went above 47.

The pollutant setting the AQI on an ordinary day here:

ozone100%2,371 days

Every recent year on file

Year	Days monitored	Good	Moderate	Over 100	Over 150	Median AQI	Highest AQI
2025*	228	221	7	0	0	36	67
2024	240	221	19	0	0	40	74
2023	241	221	20	0	0	39	84
2022	243	230	13	0	0	36	71
2021	231	227	4	0	0	34	54
2020	243	241	2	0	0	33	61
2019	242	237	5	0	0	37	58
2018	238	218	19	1	0	36	119
2017	220	214	6	0	0	36	71
2016	245	225	20	0	0	37	84
2015	242	222	20	0	0	38	100
2014	244	217	27	0	0	39	90
2013	245	232	12	1	0	37	101
2012	237	158	69	10	1	46	154
2011	245	205	36	4	1	41	151
2010	243	178	61	4	0	43	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.