EnviroNearby

Lafayette Parish, Louisiana air quality history

Daily Air Quality Index summaries from EPA monitors in Lafayette, Louisiana, 1983–2025.

66%
Good days in 2025
45
Median daily AQI, 2025
0
Days above 100 in 2025
362
Days with an AQI in 2025 (of 365)

In 2025, EPA reported a daily Air Quality Index (AQI) for Lafayette, Louisiana on 362 days. 238 of those days (66%) were in the Good range, and the median daily AQI was 45. That median is higher than the typical monitored county in Louisiana (median 42 across 21 counties), and higher than the typical monitored U.S. county (40). The main pollutant was fine particles (PM2.5) on 204 days. Across the years with fuller monitoring, the share of Good days fell: an average of 83% in 1983–1985 versus 58% in 2023–2025.

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.

Share of monitored days in each AQI category, by year0%25%50%75%100%1983: Good 165 of 200 days1983: Moderate 27 of 200 days1983: Unhealthy for Sensitive Groups 7 of 200 days1983: Unhealthy 1 of 200 days19831984: Good 315 of 355 days1984: Moderate 28 of 355 days1984: Unhealthy for Sensitive Groups 11 of 355 days1984: Unhealthy 1 of 355 days1985: Good 267 of 347 days1985: Moderate 59 of 347 days1985: Unhealthy for Sensitive Groups 15 of 347 days1985: Unhealthy 6 of 347 days1986: Good 256 of 337 days1986: Moderate 60 of 337 days1986: Unhealthy for Sensitive Groups 20 of 337 days1986: Unhealthy 1 of 337 days1987: Good 236 of 340 days1987: Moderate 71 of 340 days1987: Unhealthy for Sensitive Groups 27 of 340 days1987: Unhealthy 6 of 340 days1988: Good 246 of 328 days1988: Moderate 50 of 328 days1988: Unhealthy for Sensitive Groups 26 of 328 days1988: Unhealthy 6 of 328 days19881989: Good 289 of 352 days1989: Moderate 43 of 352 days1989: Unhealthy for Sensitive Groups 20 of 352 days1990: Good 275 of 349 days1990: Moderate 54 of 349 days1990: Unhealthy for Sensitive Groups 18 of 349 days1990: Unhealthy 2 of 349 days1991: Good 317 of 348 days1991: Moderate 25 of 348 days1991: Unhealthy for Sensitive Groups 6 of 348 days1992: Good 312 of 344 days1992: Moderate 25 of 344 days1992: Unhealthy for Sensitive Groups 6 of 344 days1992: Very Unhealthy 1 of 344 days1993: Good 308 of 358 days1993: Moderate 40 of 358 days1993: Unhealthy for Sensitive Groups 10 of 358 days19931994: Good 295 of 361 days1994: Moderate 48 of 361 days1994: Unhealthy for Sensitive Groups 17 of 361 days1994: Unhealthy 1 of 361 days1995: Good 259 of 362 days1995: Moderate 65 of 362 days1995: Unhealthy for Sensitive Groups 27 of 362 days1995: Unhealthy 10 of 362 days1995: Very Unhealthy 1 of 362 days1996: Good 286 of 355 days1996: Moderate 50 of 355 days1996: Unhealthy for Sensitive Groups 18 of 355 days1996: Unhealthy 1 of 355 days1997: Good 280 of 365 days1997: Moderate 68 of 365 days1997: Unhealthy for Sensitive Groups 16 of 365 days1997: Unhealthy 1 of 365 days1998: Good 256 of 333 days1998: Moderate 53 of 333 days1998: Unhealthy for Sensitive Groups 20 of 333 days1998: Unhealthy 4 of 333 days19981999: Good 217 of 365 days1999: Moderate 121 of 365 days1999: Unhealthy for Sensitive Groups 24 of 365 days1999: Unhealthy 3 of 365 days2000: Good 215 of 363 days2000: Moderate 115 of 363 days2000: Unhealthy for Sensitive Groups 26 of 363 days2000: Unhealthy 5 of 363 days2000: Very Unhealthy 2 of 363 days2001: Good 248 of 360 days2001: Moderate 102 of 360 days2001: Unhealthy for Sensitive Groups 10 of 360 days2002: Good 255 of 353 days2002: Moderate 90 of 353 days2002: Unhealthy for Sensitive Groups 8 of 353 days2003: Good 227 of 362 days2003: Moderate 116 of 362 days2003: Unhealthy for Sensitive Groups 17 of 362 days2003: Unhealthy 2 of 362 days20032004: Good 248 of 366 days2004: Moderate 99 of 366 days2004: Unhealthy for Sensitive Groups 18 of 366 days2004: Unhealthy 1 of 366 days2005: Good 173 of 308 days2005: Moderate 117 of 308 days2005: Unhealthy for Sensitive Groups 16 of 308 days2005: Unhealthy 2 of 308 days2006: Good 238 of 365 days2006: Moderate 113 of 365 days2006: Unhealthy for Sensitive Groups 12 of 365 days2006: Unhealthy 2 of 365 days2007: Good 257 of 365 days2007: Moderate 98 of 365 days2007: Unhealthy for Sensitive Groups 10 of 365 days2008: Good 258 of 366 days2008: Moderate 101 of 366 days2008: Unhealthy for Sensitive Groups 7 of 366 days20082009: Good 258 of 365 days2009: Moderate 104 of 365 days2009: Unhealthy for Sensitive Groups 3 of 365 days2010: Good 81 of 365 days2010: Moderate 274 of 365 days2010: Unhealthy for Sensitive Groups 10 of 365 days2011: Good 126 of 365 days2011: Moderate 234 of 365 days2011: Unhealthy for Sensitive Groups 5 of 365 days2012: Good 146 of 366 days2012: Moderate 217 of 366 days2012: Unhealthy for Sensitive Groups 3 of 366 days2013: Good 140 of 365 days2013: Moderate 223 of 365 days2013: Unhealthy for Sensitive Groups 2 of 365 days20132014: Good 123 of 364 days2014: Moderate 241 of 364 days2015: Good 167 of 365 days2015: Moderate 198 of 365 days2016: Good 244 of 366 days2016: Moderate 122 of 366 days2017: Good 218 of 365 days2017: Moderate 146 of 365 days2017: Unhealthy for Sensitive Groups 1 of 365 days2018: Good 210 of 365 days2018: Moderate 155 of 365 days20182019: Good 212 of 365 days2019: Moderate 153 of 365 days2020: Good 203 of 364 days2020: Moderate 160 of 364 days2020: Unhealthy for Sensitive Groups 1 of 364 days2021: Good 243 of 365 days2021: Moderate 122 of 365 days2022: Good 213 of 364 days2022: Moderate 149 of 364 days2022: Unhealthy for Sensitive Groups 2 of 364 days2023: Good 211 of 365 days2023: Moderate 153 of 365 days2023: Unhealthy for Sensitive Groups 1 of 365 days20232024: Good 180 of 365 days2024: Moderate 183 of 365 days2024: Unhealthy for Sensitive Groups 2 of 365 days2025: Good 238 of 362 days2025: Moderate 124 of 362 days2025
  • 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 and 90th-percentile daily AQI, by year0501001501983: 90th percentile AQI 741984: 90th percentile AQI 581985: 90th percentile AQI 801986: 90th percentile AQI 901987: 90th percentile AQI 1001988: 90th percentile AQI 1001989: 90th percentile AQI 711990: 90th percentile AQI 801991: 90th percentile AQI 491992: 90th percentile AQI 501993: 90th percentile AQI 611994: 90th percentile AQI 741995: 90th percentile AQI 1121996: 90th percentile AQI 771997: 90th percentile AQI 841998: 90th percentile AQI 871999: 90th percentile AQI 902000: 90th percentile AQI 972001: 90th percentile AQI 772002: 90th percentile AQI 652003: 90th percentile AQI 872004: 90th percentile AQI 772005: 90th percentile AQI 932006: 90th percentile AQI 872007: 90th percentile AQI 742008: 90th percentile AQI 742009: 90th percentile AQI 612010: 90th percentile AQI 802011: 90th percentile AQI 722012: 90th percentile AQI 712013: 90th percentile AQI 682014: 90th percentile AQI 672015: 90th percentile AQI 662016: 90th percentile AQI 612017: 90th percentile AQI 672018: 90th percentile AQI 652019: 90th percentile AQI 612020: 90th percentile AQI 622021: 90th percentile AQI 602022: 90th percentile AQI 632023: 90th percentile AQI 642024: 90th percentile AQI 632025: 90th percentile AQI 591983: Median AQI 261984: Median AQI 291985: Median AQI 371986: Median AQI 351987: Median AQI 391988: Median AQI 381989: Median AQI 311990: Median AQI 361991: Median AQI 291992: Median AQI 311993: Median AQI 311994: Median AQI 321995: Median AQI 381996: Median AQI 361997: Median AQI 351998: Median AQI 371999: Median AQI 442000: Median AQI 452001: Median AQI 412002: Median AQI 402003: Median AQI 432004: Median AQI 422005: Median AQI 472006: Median AQI 442007: Median AQI 402008: Median AQI 392009: Median AQI 422010: Median AQI 582011: Median AQI 542012: Median AQI 532013: Median AQI 532014: Median AQI 542015: Median AQI 522016: Median AQI 442017: Median AQI 452018: Median AQI 472019: Median AQI 462020: Median AQI 452021: Median AQI 422022: Median AQI 472023: Median AQI 472024: Median AQI 512025: Median AQI 451983198819931998200320082013201820232025
  • 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.

PollutantDays as main pollutantShare of monitored days
Fine particles (PM2.5)20456%
Ozone15844%

Year-by-year data

Annual AQI summary by year
YearDays with AQIGoodModerateUnhealthy for Sensitive GroupsUnhealthyVery UnhealthyHazardousMedian AQI90th pct.Max AQIMain pollutant
20253622381240000455979PM2.5
202436518018320005163108PM2.5
202336521115310004764112Ozone
202236421314920004763103PM2.5
20213652431220000426087PM2.5
202036420316010004562120PM2.5
20193652121530000466184PM2.5
20183652101550000476597PM2.5
201736521814610004567105PM2.5
20163662441220000446190Ozone
20153651671980000526697PM2.5
20143641232410000546797PM2.5
201336514022320005368119PM2.5
201236614621730005371129PM2.5
201136512623450005472133PM2.5
201036581274100005880129PM2.5
200936525810430004261147Ozone
200836625810170003974147Ozone
200736525798100004074122Ozone
2006365238113122004487169Ozone
2005308173117162004793159Ozone
200436624899181004277164Ozone
2003362227116172004387156Ozone
20023532559080004065143Ozone
2001360248102100004177150Ozone
2000363215115265204597208Ozone
1999365217121243004490161Ozone
199833325653204003787179Ozone
199736528068161003584174Ozone
199635528650181003677154Ozone
19953622596527101038112201Ozone
199436129548171003274172Ozone
199335830840100003161133Ozone
19923443122560103150205Ozone
19913483172560002949122Ozone
199034927554182003680177Ozone
198935228943200003171140Ozone
1988328246502660038100185Ozone
1987340236712760039100182Ozone
198633725660201003590166Ozone
198534726759156003780172Ozone
198435531528111002958159Ozone
19832001652771002674179Ozone

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 1983–2025 (EPA download page). EPA file dates: 2026-06-26. Imported into EnviroNearby November 5, 2026. How we use this data · Report a problem