Bad Air Days in Garfield County, Utah: under 1 a Year

under 1 bad air day a year

Fewer bad air days than most monitored US counties. Ranked 695 of 996 monitored counties, where 1 is worst.

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

The bad-air season here

Most bad days here fall in August and June and July. 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.

The worst days on file

The worst recent year was 2017, with 2 bad days on 240 monitored days.

Date	AQI	Main pollutant
2018-06-24	122	Ozone
2021-08-07	115	Ozone
2021-08-08	112	Ozone
2017-07-02	105	Ozone
2017-06-29	101	Ozone

The air on a normal day

Across 2,346 monitored days from 2016 to 2025, the air in Garfield County rated Good on 84% of them, more often than the 72% typical of monitored counties, and Moderate on 16%. The median day sat at AQI 37; one day in ten went above 54.

The pollutant setting the AQI on an ordinary day here:

ozone76%1,789 days
fine particles (PM2.5)24%557 days

Every recent year on file

Year	Days monitored	Good	Moderate	Over 100	Median AQI	Highest AQI
2025*	86	84	2	0	12	79
2024	119	116	3	0	9	61
2023	121	121	0	0	10	38
2022	293	246	47	0	44	93
2021	362	273	87	2	45	115
2020	365	331	34	0	42	74
2019	299	258	41	0	41	80
2018	365	259	104	2	44	122
2017	240	176	62	2	44	105
2016	96	96	0	0	11	33
2015	364	299	63	2	42	108
2014	364	342	22	0	42	80
2013	345	305	38	2	40	105
2012	366	307	57	2	42	112
2011	131	129	2	0	12	61
2010	116	115	1	0	11	52

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

Elsewhere in Utah

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.