Sumter County, Alabama air quality history

Daily Air Quality Index summaries from EPA monitors in Sumter, Alabama, 1991–2025.

78%

Good days in 2025

Median daily AQI, 2025

Days above 100 in 2025

364

Days with an AQI in 2025 (of 365)

In 2025, EPA reported a daily Air Quality Index (AQI) for Sumter, Alabama on 364 days. 284 of those days (78%) were in the Good range, and the median daily AQI was 41. That median is about the same as the typical monitored county in Alabama (median 41 across 14 counties), and about the same as the typical monitored U.S. county (40). The main pollutant was fine particles (PM2.5) on 294 days. Across the years with fuller monitoring, the share of Good days fell: an average of 86% in 1992–1994 versus 82% in 2023–2025.

Years with fewer than 120 monitored days (1991) 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, 2025

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)	294	81%
Ozone	70	19%

Year-by-year data

Annual AQI summary by year
Year	Days with AQI	Good	Moderate	Unhealthy for Sensitive Groups	Unhealthy	Median AQI	90th pct.	Max AQI	Main pollutant
2025	364	284	80	0	0	41	54	90	PM2.5
2024	366	309	57	0	0	36	53	73	PM2.5
2023	363	303	60	0	0	35	55	84	PM2.5
2022	355	266	89	0	0	38	56	81	PM2.5
2021	355	311	44	0	0	35	52	71	PM2.5
2020	355	314	41	0	0	33	51	74	PM2.5
2019	354	287	67	0	0	38	54	67	PM2.5
2018	357	327	30	0	0	31	48	77	Ozone
2017	350	279	71	0	0	38	54	85	PM2.5
2016	336	282	54	0	0	37	53	74	PM2.5
2015	314	169	144	1	0	48	62	107	PM2.5
2014	241	232	9	0	0	34	47	74	Ozone
2013	220	213	7	0	0	31	43	90	Ozone
2011	198	174	24	0	0	38	54	93	Ozone
2010	242	206	35	1	0	39	64	119	Ozone
2009	239	237	2	0	0	31	44	61	Ozone
2008	242	227	15	0	0	31	49	84	Ozone
2007	239	191	46	2	0	40	74	140	Ozone
2006	263	179	82	2	0	43	71	119	Ozone
2005	272	187	83	2	0	44	67	117	Ozone
2004	269	186	83	0	0	42	64	93	Ozone
2003	281	190	91	0	0	43	65	99	Ozone
2002	285	191	86	7	1	41	71	179	Ozone
2001	274	169	99	5	1	44	74	164	Ozone
2000	273	153	100	20	0	47	93	147	Ozone
1999	259	136	112	11	0	49	80	143	Ozone
1998	194	168	24	2	0	37	61	122	Ozone
1997	212	191	21	0	0	35	50	84	Ozone
1996	230	201	27	2	0	36	58	108	Ozone
1995	280	230	45	5	0	37	67	119	Ozone
1994	315	283	30	2	0	31	51	136	Ozone
1993	293	255	38	0	0	37	58	100	Ozone
1992	206	166	34	6	0	39	67	140	Ozone
1991	45	42	3	0	0	30	48	77	Ozone

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.

Counties in Alabama with a similar median AQI in 2025

All monitored counties in Alabama

Source: U.S. EPA AirData, “Annual AQI by County” files for 1991–2025 (EPA download page). EPA file dates: 2026-06-26. Imported into EnviroNearby November 5, 2026. How we use this data · Report a problem