Steuben County, New York air quality history

Daily Air Quality Index summaries from EPA monitors in Steuben, New York, 1990–2025.

83%

Good days in 2025

Median daily AQI, 2025

Days above 100 in 2025

365

Days with an AQI in 2025 (of 365)

In 2025, EPA reported a daily Air Quality Index (AQI) for Steuben, New York on 365 days. 304 of those days (83%) were in the Good range, and the median daily AQI was 38. That median is about the same as the typical monitored county in New York (median 36 across 27 counties), and about the same as the typical monitored U.S. county (40). The main pollutant was ozone on 271 days. Across the years with fuller monitoring, the share of Good days rose: an average of 56% in 2000–2002 versus 82% in 2023–2025.

Years with fewer than 120 monitored days (1992, 1993, 1994, 1995, 1996, 1999…) 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
Ozone	271	74%
Fine particles (PM2.5)	94	26%

Year-by-year data

Annual AQI summary by year
Year	Days with AQI	Good	Moderate	Unhealthy for Sensitive Groups	Unhealthy	Very Unhealthy	Median AQI	90th pct.	Max AQI	Main pollutant
2025	365	304	58	3	0	0	38	57	143	Ozone
2024	365	321	44	0	0	0	37	52	68	Ozone
2023	365	274	83	3	4	1	40	64	256	Ozone
2022	365	326	39	0	0	0	38	51	71	Ozone
2021	365	285	79	1	0	0	38	59	124	Ozone
2020	365	330	35	0	0	0	36	49	81	Ozone
2019	365	315	50	0	0	0	37	53	69	Ozone
2018	363	313	50	0	0	0	34	52	87	Ozone
2017	365	339	26	0	0	0	35	48	92	Ozone
2016	363	321	40	2	0	0	37	51	122	Ozone
2015	358	290	68	0	0	0	36	56	80	Ozone
2014	365	318	47	0	0	0	35	52	77	Ozone
2013	365	332	33	0	0	0	33	49	84	Ozone
2012	366	318	48	0	0	0	35	53	100	Ozone
2011	360	297	61	1	1	0	41	58	160	Ozone
2010	365	260	105	0	0	0	38	61	100	PM2.5
2009	365	263	101	1	0	0	40	61	101	PM2.5
2008	362	222	136	4	0	0	44	67	143	PM2.5
2007	365	213	143	9	0	0	46	76	122	PM2.5
2006	365	238	121	6	0	0	42	69	115	PM2.5
2005	340	192	146	2	0	0	44	73	123	PM2.5
2004	335	204	127	4	0	0	39	67	123	PM2.5
2003	330	191	137	2	0	0	44	67	128	PM2.5
2002	343	193	142	8	0	0	46	73	147	PM2.5
2001	334	173	154	7	0	0	48	73	150	PM2.5
2000	305	186	119	0	0	0	42	68	99	PM2.5
1999	108	68	40	0	0	0	38	67	81	PM2.5
1996	27	27	0	0	0	0	14	22	27	PM10
1995	54	54	0	0	0	0	16	30	42	PM10
1994	60	60	0	0	0	0	16	31	48	PM10
1993	56	55	1	0	0	0	16	31	54	PM10
1992	57	57	0	0	0	0	19	31	41	PM10
1991	55	52	3	0	0	0	21	43	55	PM10
1990	25	25	0	0	0	0	18	37	43	PM10

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 New York with a similar median AQI in 2025

All monitored counties in New York

Source: U.S. EPA AirData, “Annual AQI by County” files for 1990–2025 (EPA download page). EPA file dates: 2026-06-26. Imported into EnviroNearby November 5, 2026. How we use this data · Report a problem