Terrebonne Parish, Louisiana air quality history

Daily Air Quality Index summaries from EPA monitors in Terrebonne, Louisiana, 2000–2025.

73%

Good days in 2025

Median daily AQI, 2025

Days above 100 in 2025

122

Days with an AQI in 2025 (of 365)

In 2025, EPA reported a daily Air Quality Index (AQI) for Terrebonne, Louisiana on 122 days. 89 of those days (73%) were in the Good range, and the median daily AQI was 42. That median is about the same as the typical monitored county in Louisiana (median 42 across 21 counties), and about the same as the typical monitored U.S. county (40). The main pollutant was fine particles (PM2.5) on 122 days. Across the years with fuller monitoring, the share of Good days rose: an average of 48% in 2002–2005 versus 72% in 2022–2025.

EPA did not report an AQI for every day of 2025 here (122 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, 2012, 2013, 2018, 2021, 2023…) 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)	122	100%

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	122	89	33	0	0	42	58	66	PM2.5
2024	123	85	38	0	0	39	58	99	PM2.5
2023	115	77	35	2	1	43	58	176	PM2.5
2022	121	90	31	0	0	38	55	96	PM2.5
2021	110	89	21	0	0	34	56	64	PM2.5
2020	120	92	28	0	0	36	56	77	PM2.5
2019	120	93	27	0	0	37	57	73	PM2.5
2018	119	95	24	0	0	36	56	73	PM2.5
2017	120	90	30	0	0	37	56	88	PM2.5
2016	120	97	23	0	0	37	53	76	PM2.5
2015	122	95	27	0	0	34	55	79	PM2.5
2014	121	87	34	0	0	38	57	67	PM2.5
2013	117	91	26	0	0	38	56	70	PM2.5
2012	118	86	32	0	0	37	59	72	PM2.5
2011	123	76	47	0	0	44	59	71	PM2.5
2010	120	71	49	0	0	47	58	71	PM2.5
2009	120	80	40	0	0	42	58	69	PM2.5
2008	107	68	39	0	0	43	61	77	PM2.5
2007	113	64	49	0	0	44	68	84	PM2.5
2006	116	53	62	0	1	52	74	163	PM2.5
2005	121	57	64	0	0	52	69	93	PM2.5
2004	111	64	46	1	0	44	67	125	PM2.5
2003	120	57	63	0	0	52	70	100	PM2.5
2002	122	62	60	0	0	50	59	75	PM2.5
2001	114	53	61	0	0	52	69	86	PM2.5
2000	117	41	76	0	0	55	73	96	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.

Counties in Louisiana with a similar median AQI in 2025

All monitored counties in Louisiana

Source: U.S. EPA AirData, “Annual AQI by County” files for 2000–2025 (EPA download page). EPA file dates: 2026-06-26. Imported into EnviroNearby November 5, 2026. How we use this data · Report a problem