Bad Air Days in Hancock County, West Virginia: under 1 a Year

under 1 bad air day a year

Fewer bad air days than most monitored US counties. Ranked 699 of 996 monitored counties, where 1 is worst.

What makes them bad: mostly ozone: summer smog (33% particle days).

The bad-air season here

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

What actually helps 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.

The worst days on file

In 2000 to 2009 this county averaged 17 bad days a year; in 2016 to 2025, under 1. The air has improved. The worst recent year was 2023, with 6 bad days on 364 monitored days.

Date	AQI	Main pollutant
2023-06-29	181	PM2.5
2020-07-09	133	Ozone
2023-04-11	129	Ozone
2023-06-28	124	PM10
2023-07-17	111	PM2.5

An ordinary day in Hancock

Across 3,526 monitored days from 2016 to 2025, the air in Hancock County rated Good on 80% of them, more often than the 72% typical of monitored counties, and Moderate on 19%. The median day sat at AQI 38; one day in ten went above 58.

The pollutant setting the AQI on an ordinary day here:

ozone54%1,896 days
fine particles (PM2.5)28%997 days
coarse dust (PM10)18%628 days

Every recent year on file

Year	Days monitored	Good	Moderate	Over 100	Over 150	Median AQI	Highest AQI
2025*	365	255	109	1	0	42	101
2024	364	262	102	0	0	41	97
2023	364	287	71	6	1	36	181
2022	365	317	48	0	0	34	100
2021	364	286	78	0	0	38	93
2020	307	262	44	1	0	37	133
2019	303	257	46	0	0	40	93
2018	363	308	54	1	0	35	105
2017	365	303	62	0	0	38	87
2016	366	300	66	0	0	36	93
2015	365	284	79	2	0	36	112
2014	365	288	76	1	0	36	112
2013	365	276	86	3	0	37	140
2012	366	252	102	12	0	41	143
2011	365	259	100	6	0	39	133
2010	365	233	122	10	0	43	143

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

Nearby counties on file

Ohio County1/yr
Berkeley County1/yr
Wood Countyunder 1/yr
Marshall Countyunder 1/yr
Kanawha Countyunder 1/yr
Cabell Countyunder 1/yr
Brooke Countyunder 1/yr
Marion Countythin data

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.