Air quality in Lafourche Parish, LA

Includes Thibodaux · EPA monitor readings, 2021 to 2025 · 98,000 people

Clean most days
Bad-air days a year
<1
day with an AQI over 100

4 bad-air days in 5 years of readings, 2021 to 2025. That's down from about 23 a year in the early 2000s. Lafourche Parish is tied with 1 other Louisiana county for the 5th fewest bad-air days of the 19 with monitors.

0days unhealthy for everyoneAQI over 150, a year
47AQI on a typical dayGood: fine for everyone
7bad-air days since 2016Too few to show a season
126worst day since 2016Sep 6, 2019, ozone
How to read the AQIThe EPA's air score runs from 0 to 500. Higher is worse. Over 100 counts as a bad-air day.
Typical day 47 (Good)Worst day 126 (Unhealthy for sensitive groups)
Good0 to 50Moderate51 to 100Sensitive groups101 to 150Unhealthy151 to 200Very unhealthy201 to 300Hazardous301 to 500

Bad-air days by month in Lafourche Parish

Bad air is rare here: 7 bad-air days in 10 years of daily readings since 2016, too few to show a season. Each tile is the average for that month.

Jan0
Feb0
Mar0
Apr0
May0
Jun0.2
Jul0
Aug0.1
Sep0.1
Oct0.1
Nov0.1
Dec0.1

The worst day since 2016 was September 6, 2019: AQI 126, from ozone.

What causes it

The 7 bad-air days since 2016 were 4 ozone days (in June 2019, September 2019, October 2020 and August 2023) and 3 fine-particle days (in June 2022, December 2024 and November 2025).

CDC estimates by month, 2001 to 2022

The CDC's model counts bad-air days at the county's worst spot, from monitors and satellites. Particles (brown) fill the inside of the ring and ozone (blue) the outside.

January: 0.0 smoky days a yearJFMarch: 0.1 smoky days a yearMarch: 0.4 ozone days a yearMApril: 1.3 ozone days a yearAMay: 2.1 ozone days a yearMJune: 2.0 ozone days a yearJJuly: 0.4 ozone days a yearJAugust: 0.9 ozone days a yearASeptember: 0.4 smoky days a yearSeptember: 1.7 ozone days a yearSOctober: 0.1 smoky days a yearOctober: 1.2 ozone days a yearONovember: 0.5 smoky days a yearNovember: 0.1 ozone days a yearNDecember: 0.1 smoky days a yearDbad daysby month
See the numbers by month
CDC estimated bad-air days a year in each month in Lafourche Parish, 2001 to 2022
MonthFine particlesOzone
January00
February00
March0.10.4
April01.3
May02.1
June02.0
July00.4
August00.9
September0.41.7
October0.11.2
November0.50.1
December0.10

What helps in Lafourche Parish

The air here is clean most days: 7 bad-air days in 10 years of daily readings. Wildfire smoke can still drift in from far away, so it's worth being ready.

Check tomorrow's forecast

AirNow posts an air quality forecast by ZIP code, usually the day before.

AirNow →

Keep a cheap backup

A box fan with a MERV 13 filter clamped to it cleans a room in a pinch.

Build one →

Keep one room clean on smoky days

Shut the windows and run an air purifier sized for the room.

Choosing a purifier →

For today's reading and tomorrow's forecast, check AirNow by ZIP code. Its fire and smoke map adds smoke plumes.

Smoky days are rare here, so a purifier is optional. If you want one for wildfire season anyway, see the 3 models we'd buy, each with a verified smoke rating.

Every year since 2000

Bad-air days each year. The striped part is days unhealthy for everyone, over AQI 150. The worst recent year was 2022, with 1 bad-air day.

020406020004020052010201520202025102040602000402010202020251
Unhealthy for sensitive groups (101 to 150)Unhealthy or worse (over 150)
See the numbers by year
Bad-air days each year in Lafourche Parish
YearBad-air daysOver 150
2000403
2001214
200260
2003270
2004190
2005241
2006162
2007141
200860
200920
201080
201160
201240
201310
201410
201500
201600
201700
201800
201920
202010
202100
202210
202310
202410
202510

Lafourche Parish and its neighbors

Bad-air days a year, 2021 to 2025. Louisiana counties with monitors averaged about 2 bad-air days a year, weighted by population.

Jefferson Parish2
St. John the Baptist Parish1
St. James Parish1
Lafourche Parish<1

Nearest counties with a full report: Orleans Parish, LA (under 1 bad-air day a year), St. Tammany Parish, LA (under 1 bad-air day a year).

Questions people ask about air in Lafourche Parish

How often is the air bad in Lafourche Parish?

From 2021 to 2025, monitors in Lafourche Parish recorded about 1 bad-air day a year with an AQI above 100, which is unhealthy for sensitive groups or worse. The worst year in that stretch was 2022, with 1 bad-air day.

What causes bad air in Lafourche Parish?

The 7 bad-air days since 2016 were 4 ozone days (in June 2019, September 2019, October 2020 and August 2023) and 3 fine-particle days (in June 2022, December 2024 and November 2025).

Where can I see today's air quality in Lafourche Parish?

AirNow, run by the EPA and its partners, shows the current AQI and tomorrow's forecast for your ZIP code. Its fire and smoke map adds smoke plumes. On a typical day the AQI in Lafourche Parish is about 47, which is good, fine for everyone. Bad days are rare here, so check it when wildfire smoke is in the news.

About these numbers

Day counts come from the EPA's county air quality summaries, which take the worst reading across a county's monitors each day. Monitors here reported on about 358 days a year from 2021 to 2025. A county is large, and your street can be cleaner or worse. CDC's model, which estimates every county from monitors and satellites, gives the worst spot in Lafourche Parish almost no high-particle days and about 1 high-ozone day a year from 2018 to 2022.

Sources: EPA AirData county AQI summaries (2000 to 2025) and daily county AQI (2016 to 2025); CDC Environmental Public Health Tracking Network modeled PM2.5 and ozone (2001 to 2022). Updated November 8, 2026.