Bad Air Days in Henry County, Indiana: 2 a Year

2 bad air days a year

About the middle of monitored US counties. Ranked 487 of 996 monitored counties, where 1 is worst.

What makes them bad: mostly particles: smoke and dust (100% particle days).

When the bad days come in Henry

Most bad days here fall in June 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 record for Henry

The worst recent year was 2023, with 10 bad days on 348 monitored days.

Date	AQI	Main pollutant
2023-06-27	192	PM2.5
2023-06-28	188	PM2.5
2023-06-29	141	PM2.5
2023-07-17	131	PM2.5
2023-06-07	128	PM2.5

The air on a normal day

Across 1,894 monitored days from 2016 to 2025, the air in Henry County rated Good on 71% of them, close to the 72% typical of monitored counties, and Moderate on 29%. The median day sat at AQI 38; one day in ten went above 59.

The pollutant setting the AQI on an ordinary day here:

fine particles (PM2.5)100%1,894 days

Year by year

Year	Days monitored	Good	Moderate	Over 100	Over 150	Median AQI	Highest AQI
2025*	365	255	110	0	0	37	95
2024	361	282	79	0	0	34	75
2023	348	214	124	10	2	44	192
2022	111	87	24	0	0	34	95
2021	117	78	39	0	0	38	82
2020	118	87	31	0	0	39	67
2019	119	81	38	0	0	37	67
2018	116	80	35	1	0	41	111
2017	120	86	34	0	0	38	66
2016	119	87	32	0	0	37	69
2015	121	77	44	0	0	38	75
2014	121	66	54	1	0	48	119
2013	120	62	58	0	0	49	87
2012	119	65	54	0	0	47	76
2011	120	56	64	0	0	52	93
2010	117	43	73	1	0	55	107

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

Indiana compared

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.