Garfield County, Utah air quality history

Daily Air Quality Index summaries from EPA monitors in Garfield, Utah, 1988–2025.

100%

Good days in 2023

Median daily AQI, 2023

Days above 100 in 2023

121

Days with an AQI in 2023 (of 365)

In 2023, EPA reported a daily Air Quality Index (AQI) for Garfield, Utah on 121 days. 121 of those days (100%) were in the Good range, and the median daily AQI was 10. That median is lower than the typical monitored county in Utah (median 47 across 15 counties), and lower than the typical monitored U.S. county (43). The main pollutant was fine particles (PM2.5) on 121 days. Across the years with fuller monitoring, the share of Good days fell: an average of 90% in 2011–2013 versus 86% in 2021–2023.

EPA did not report an AQI for every day of 2023 here (121 of 365 days). Figures describe monitored days only; seasonal monitoring (for example, ozone measured only in warmer months) can make a county look cleaner or dirtier than a full-year record would.

Years with fewer than 120 monitored days (2008, 2009, 2010, 2016, 2024, 2025…) are shown in the table but left out of comparisons and trend statements.

How the days broke down each year

Each bar is one year. The colored segments show the share of monitored days that fell in each AQI category.

Good
Moderate
Unhealthy for Sensitive Groups
Unhealthy
Very Unhealthy
Hazardous

Typical and high-end AQI over time

The median is the middle day of the year. The 90th percentile is the level that only the highest 10% of days exceeded.

Median daily AQI
90th-percentile daily AQI

Main pollutant by day, 2023

On each monitored day, the AQI reflects whichever measured pollutant had the highest index. This counts how many days each pollutant set the AQI. A pollutant that was not measured here cannot appear.

Pollutant	Days as main pollutant	Share of monitored days
Fine particles (PM2.5)	121	100%

Year-by-year data

Annual AQI summary by year
Year	Days with AQI	Good	Moderate	Unhealthy for Sensitive Groups	Median AQI	90th pct.	Max AQI	Main pollutant
2025	86	84	2	0	12	22	79	PM2.5
2024	119	116	3	0	9	26	61	PM2.5
2023	121	121	0	0	10	19	38	PM2.5
2022	293	246	47	0	44	58	93	Ozone
2021	362	273	87	2	45	64	115	Ozone
2020	365	331	34	0	42	50	74	Ozone
2019	299	258	41	0	41	51	80	Ozone
2018	365	259	104	2	44	74	122	Ozone
2017	240	176	62	2	44	71	105	Ozone
2016	96	96	0	0	11	24	33	PM2.5
2015	364	299	63	2	42	58	108	Ozone
2014	364	342	22	0	42	49	80	Ozone
2013	345	305	38	2	40	51	105	Ozone
2012	366	307	57	2	42	61	112	Ozone
2011	131	129	2	0	12	33	61	PM2.5
2010	116	115	1	0	11	19	52	PM2.5
2009	118	114	4	0	12	28	68	PM2.5
2008	112	107	5	0	13	26	67	PM2.5
2007	117	113	4	0	15	31	65	PM2.5
2006	118	118	0	0	13	27	42	PM2.5
2005	113	111	2	0	11	24	55	PM2.5
2004	116	116	0	0	12	24	34	PM2.5
2003	118	117	1	0	12	26	51	PM2.5
2002	103	101	2	0	11	33	55	PM2.5
2001	107	105	2	0	14	24	63	PM2.5
2000	101	99	2	0	12	26	59	PM2.5
1999	86	86	0	0	15	28	45	PM2.5
1998	101	100	1	0	13	24	59	PM2.5
1997	105	104	1	0	14	29	82	PM2.5
1996	101	98	3	0	16	33	64	PM2.5
1995	101	101	0	0	14	27	41	PM2.5
1994	96	95	1	0	19	32	51	PM2.5
1993	90	89	1	0	17	28	58	PM2.5
1992	66	66	0	0	16	26	29	PM2.5
1991	102	102	0	0	17	27	43	PM2.5
1990	95	95	0	0	16	32	49	PM2.5
1989	100	100	0	0	18	31	48	PM2.5
1988	76	75	1	0	19	31	51	PM2.5

What this data can and can’t tell you

It is a county-level summary. EPA reports one AQI per day for the county, based on the monitors operating there. Air at a particular street, school or home can differ, especially near roads, industry or wildfire smoke.

It is not a health assessment. The AQI is EPA’s scale for communicating daily air quality. A county’s history can’t tell you what the health risk is for any particular person. For daily conditions and health guidance, see AirNow.

Rules change over time. EPA has revised AQI breakpoints, most recently for fine particles in 2024, so some year-to-year change can reflect the scale rather than the air.

All monitored counties in Utah

Source: U.S. EPA AirData, “Annual AQI by County” files for 1988–2025 (EPA download page). EPA file dates: 2026-06-26. Imported into EnviroNearby November 5, 2026. How we use this data · Report a problem