Grant Parish, Louisiana air quality history

Daily Air Quality Index summaries from EPA monitors in Grant, Louisiana, 1980–2005.

80%

Good days in 2005

Median daily AQI, 2005

Days above 100 in 2005

218

Days with an AQI in 2005 (of 365)

In 2005, EPA reported a daily Air Quality Index (AQI) for Grant, Louisiana on 218 days. 175 of those days (80%) were in the Good range, and the median daily AQI was 41. That median is lower than the typical monitored county in Louisiana (median 48 across 23 counties), and lower than the typical monitored U.S. county (44). The main pollutant was ozone on 218 days. Across the years with fuller monitoring, the share of Good days held roughly steady: an average of 82% in 1980–1989 versus 83% in 2003–2005.

EPA did not report an AQI for every day of 2005 here (218 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.

The most recent year with data for this county is 2005; EPA's files for 2006–2025 contain no row for it, which usually means its monitors stopped reporting.

Years with fewer than 120 monitored days (1981, 1993) 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, 2005

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	218	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
2005	218	175	39	4	0	41	71	119	Ozone
2004	355	293	54	8	0	37	67	133	Ozone
2003	361	310	45	5	1	36	61	151	Ozone
2002	354	317	31	6	0	35	51	140	Ozone
2001	358	285	62	10	1	39	74	151	Ozone
2000	355	243	87	25	0	42	93	150	Ozone
1999	355	230	88	36	1	44	101	154	Ozone
1998	360	265	67	27	1	42	93	166	Ozone
1997	359	256	89	14	0	40	77	136	Ozone
1996	344	280	61	3	0	38	67	126	Ozone
1995	356	253	78	22	3	42	90	159	Ozone
1993	38	38	0	0	0	26	43	48	Ozone
1992	346	335	11	0	0	31	44	84	Ozone
1991	221	205	14	2	0	29	47	143	Ozone
1990	327	254	57	16	0	38	84	143	Ozone
1989	343	282	53	7	1	34	67	159	Ozone
1982	144	118	22	4	0	38	71	140	Ozone
1981	107	75	28	4	0	39	77	140	Ozone
1980	183	152	25	5	1	35	71	169	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 Louisiana with a similar median AQI in 2005

All monitored counties in Louisiana

Source: U.S. EPA AirData, “Annual AQI by County” files for 1980–2005 (EPA download page). EPA file dates: 2026-06-26. Imported into EnviroNearby November 5, 2026. How we use this data · Report a problem