Galveston County, Texas air quality history

Daily Air Quality Index summaries from EPA monitors in Galveston, Texas, 1980–2025.

60%

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 Galveston, Texas on 365 days. 218 of those days (60%) were in the Good range, and the median daily AQI was 45. That median is about the same as the typical monitored county in Texas (median 43.5 across 44 counties), and higher than the typical monitored U.S. county (40). The main pollutant was ozone on 219 days. Across the years with fuller monitoring, the share of Good days fell: an average of 71% in 1980–1983 versus 59% in 2023–2025.

Years with fewer than 120 monitored days (1981) 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	219	60%
Fine particles (PM2.5)	146	40%

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	218	139	6	2	0	45	68	179	Ozone
2024	362	245	109	6	2	0	44	67	159	Ozone
2023	362	177	164	19	2	0	51	74	159	PM2.5
2022	365	236	122	6	1	0	46	66	159	Ozone
2021	361	259	99	3	0	0	43	63	122	Ozone
2020	360	238	119	3	0	0	44	66	143	Ozone
2019	362	247	107	8	0	0	43	63	136	Ozone
2018	364	306	48	9	0	1	34	59	202	Ozone
2017	356	265	85	6	0	0	41	64	143	Ozone
2016	365	256	103	6	0	0	44	67	147	Ozone
2015	365	255	92	15	3	0	44	74	190	Ozone
2014	365	247	114	4	0	0	43	62	119	Ozone
2013	364	268	95	1	0	0	43	59	112	PM2.5
2012	365	236	121	8	0	0	45	67	150	PM2.5
2011	361	185	164	10	1	1	50	77	207	PM2.5
2010	364	232	118	13	1	0	45	62	164	PM2.5
2009	358	188	164	6	0	0	48	67	150	PM2.5
2008	303	172	128	2	1	0	47	69	195	PM2.5
2007	365	171	177	13	4	0	51	78	182	PM2.5
2006	364	170	181	11	2	0	52	77	164	PM2.5
2005	354	147	195	10	2	0	52	80	156	PM2.5
2004	366	232	105	21	6	2	43	93	206	Ozone
2003	364	239	94	19	10	2	44	93	238	Ozone
2002	365	232	109	18	6	0	44	84	185	Ozone
2001	365	229	123	10	3	0	44	77	159	Ozone
2000	366	229	106	23	6	2	42	92	225	Ozone
1999	365	244	73	24	18	6	42	112	227	Ozone
1998	365	267	60	26	7	5	38	101	249	Ozone
1997	365	272	50	26	13	4	38	112	245	Ozone
1996	330	293	27	9	1	0	31	54	154	Ozone
1995	320	220	47	27	16	10	37	133	251	Ozone
1994	310	255	35	15	4	1	35	77	206	Ozone
1993	325	288	22	6	5	4	30	54	238	Ozone
1992	328	314	12	1	1	0	30	45	177	Ozone
1991	353	317	22	8	5	1	29	51	217	Ozone
1990	341	288	37	8	6	2	30	71	219	Ozone
1989	318	250	46	14	6	2	34	87	222	Ozone
1988	140	138	2	0	0	0	21	37	95	PM10
1987	338	264	49	19	6	0	33	87	192	Ozone
1986	273	263	10	0	0	0	23	41	83	PM10
1985	354	276	51	17	2	8	34	87	218	Ozone
1984	315	234	47	23	8	3	37	101	213	Ozone
1983	209	159	28	12	8	2	37	101	207	Ozone
1982	196	117	36	22	15	6	44	156	214	Ozone
1981	48	46	1	1	0	0	33	44	101	Ozone
1980	325	251	32	17	17	8	29	122	235	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 Texas with a similar median AQI in 2025

All monitored counties in Texas

Source: U.S. EPA AirData, “Annual AQI by County” files for 1980–2025 (EPA download page). EPA file dates: 2026-06-26. Imported into EnviroNearby November 5, 2026. How we use this data · Report a problem