EnviroNearby

Jefferson Parish, Louisiana air quality history

Daily Air Quality Index summaries from EPA monitors in Jefferson, Louisiana, 1982–2025.

62%
Good days in 2025
47
Median daily AQI, 2025
1
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 Jefferson, Louisiana on 365 days. 227 of those days (62%) were in the Good range, and the median daily AQI was 47. 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 211 days. Across the years with fuller monitoring, the share of Good days fell: an average of 70% in 1982–1984 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%1982: Good 135 of 234 days1982: Moderate 56 of 234 days1982: Unhealthy for Sensitive Groups 25 of 234 days1982: Unhealthy 11 of 234 days1982: Very Unhealthy 7 of 234 days19821983: Good 269 of 355 days1983: Moderate 52 of 355 days1983: Unhealthy for Sensitive Groups 25 of 355 days1983: Unhealthy 9 of 355 days1984: Good 277 of 366 days1984: Moderate 63 of 366 days1984: Unhealthy for Sensitive Groups 18 of 366 days1984: Unhealthy 8 of 366 days1985: Good 268 of 365 days1985: Moderate 73 of 365 days1985: Unhealthy for Sensitive Groups 20 of 365 days1985: Unhealthy 3 of 365 days1985: Very Unhealthy 1 of 365 days1986: Good 247 of 365 days1986: Moderate 81 of 365 days1986: Unhealthy for Sensitive Groups 32 of 365 days1986: Unhealthy 5 of 365 days1987: Good 218 of 365 days1987: Moderate 91 of 365 days1987: Unhealthy for Sensitive Groups 42 of 365 days1987: Unhealthy 13 of 365 days1987: Very Unhealthy 1 of 365 days19871988: Good 246 of 366 days1988: Moderate 76 of 366 days1988: Unhealthy for Sensitive Groups 29 of 366 days1988: Unhealthy 15 of 366 days1989: Good 290 of 365 days1989: Moderate 64 of 365 days1989: Unhealthy for Sensitive Groups 9 of 365 days1989: Unhealthy 1 of 365 days1989: Very Unhealthy 1 of 365 days1990: Good 285 of 365 days1990: Moderate 63 of 365 days1990: Unhealthy for Sensitive Groups 15 of 365 days1990: Unhealthy 2 of 365 days1991: Good 314 of 365 days1991: Moderate 47 of 365 days1991: Unhealthy for Sensitive Groups 3 of 365 days1991: Unhealthy 1 of 365 days1992: Good 306 of 366 days1992: Moderate 52 of 366 days1992: Unhealthy for Sensitive Groups 8 of 366 days19921993: Good 284 of 365 days1993: Moderate 68 of 365 days1993: Unhealthy for Sensitive Groups 12 of 365 days1993: Unhealthy 1 of 365 days1994: Good 324 of 365 days1994: Moderate 30 of 365 days1994: Unhealthy for Sensitive Groups 9 of 365 days1994: Unhealthy 2 of 365 days1995: Good 266 of 359 days1995: Moderate 58 of 359 days1995: Unhealthy for Sensitive Groups 30 of 359 days1995: Unhealthy 5 of 359 days1996: Good 286 of 366 days1996: Moderate 63 of 366 days1996: Unhealthy for Sensitive Groups 16 of 366 days1996: Unhealthy 1 of 366 days1997: Good 287 of 364 days1997: Moderate 62 of 364 days1997: Unhealthy for Sensitive Groups 13 of 364 days1997: Unhealthy 2 of 364 days19971998: Good 278 of 363 days1998: Moderate 62 of 363 days1998: Unhealthy for Sensitive Groups 16 of 363 days1998: Unhealthy 7 of 363 days1999: Good 91 of 365 days1999: Moderate 231 of 365 days1999: Unhealthy for Sensitive Groups 35 of 365 days1999: Unhealthy 8 of 365 days2000: Good 106 of 366 days2000: Moderate 214 of 366 days2000: Unhealthy for Sensitive Groups 38 of 366 days2000: Unhealthy 8 of 366 days2001: Good 137 of 365 days2001: Moderate 199 of 365 days2001: Unhealthy for Sensitive Groups 26 of 365 days2001: Unhealthy 3 of 365 days2002: Good 158 of 365 days2002: Moderate 196 of 365 days2002: Unhealthy for Sensitive Groups 11 of 365 days20022003: Good 134 of 365 days2003: Moderate 215 of 365 days2003: Unhealthy for Sensitive Groups 12 of 365 days2003: Unhealthy 4 of 365 days2004: Good 138 of 366 days2004: Moderate 216 of 366 days2004: Unhealthy for Sensitive Groups 10 of 366 days2004: Unhealthy 2 of 366 days2005: Good 90 of 353 days2005: Moderate 239 of 353 days2005: Unhealthy for Sensitive Groups 22 of 353 days2005: Unhealthy 2 of 353 days2006: Good 98 of 365 days2006: Moderate 244 of 365 days2006: Unhealthy for Sensitive Groups 22 of 365 days2006: Unhealthy 1 of 365 days2007: Good 139 of 365 days2007: Moderate 208 of 365 days2007: Unhealthy for Sensitive Groups 14 of 365 days2007: Unhealthy 4 of 365 days20072008: Good 152 of 342 days2008: Moderate 187 of 342 days2008: Unhealthy for Sensitive Groups 3 of 342 days2009: Good 187 of 365 days2009: Moderate 171 of 365 days2009: Unhealthy for Sensitive Groups 7 of 365 days2010: Good 137 of 365 days2010: Moderate 217 of 365 days2010: Unhealthy for Sensitive Groups 10 of 365 days2010: Unhealthy 1 of 365 days2011: Good 159 of 365 days2011: Moderate 198 of 365 days2011: Unhealthy for Sensitive Groups 8 of 365 days2012: Good 205 of 360 days2012: Moderate 150 of 360 days2012: Unhealthy for Sensitive Groups 5 of 360 days20122013: Good 256 of 363 days2013: Moderate 105 of 363 days2013: Unhealthy for Sensitive Groups 2 of 363 days2014: Good 206 of 365 days2014: Moderate 154 of 365 days2014: Unhealthy for Sensitive Groups 5 of 365 days2015: Good 226 of 365 days2015: Moderate 139 of 365 days2016: Good 290 of 366 days2016: Moderate 75 of 366 days2016: Unhealthy for Sensitive Groups 1 of 366 days2017: Good 249 of 365 days2017: Moderate 114 of 365 days2017: Unhealthy for Sensitive Groups 2 of 365 days20172018: Good 207 of 365 days2018: Moderate 157 of 365 days2018: Unhealthy for Sensitive Groups 1 of 365 days2019: Good 269 of 365 days2019: Moderate 96 of 365 days2020: Good 280 of 366 days2020: Moderate 86 of 366 days2021: Good 277 of 355 days2021: Moderate 76 of 355 days2021: Unhealthy for Sensitive Groups 2 of 355 days2022: Good 219 of 362 days2022: Moderate 143 of 362 days20222023: Good 181 of 364 days2023: Moderate 179 of 364 days2023: Unhealthy for Sensitive Groups 4 of 364 days2024: Good 224 of 366 days2024: Moderate 141 of 366 days2024: Unhealthy 1 of 366 days2025: Good 227 of 365 days2025: Moderate 137 of 365 days2025: Unhealthy for Sensitive Groups 1 of 365 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 year0501001501982: 90th percentile AQI 1361983: 90th percentile AQI 971984: 90th percentile AQI 901985: 90th percentile AQI 871986: 90th percentile AQI 1011987: 90th percentile AQI 1221988: 90th percentile AQI 1151989: 90th percentile AQI 741990: 90th percentile AQI 841991: 90th percentile AQI 611992: 90th percentile AQI 671993: 90th percentile AQI 741994: 90th percentile AQI 581995: 90th percentile AQI 1001996: 90th percentile AQI 771997: 90th percentile AQI 771998: 90th percentile AQI 871999: 90th percentile AQI 1082000: 90th percentile AQI 1052001: 90th percentile AQI 912002: 90th percentile AQI 712003: 90th percentile AQI 792004: 90th percentile AQI 752005: 90th percentile AQI 942006: 90th percentile AQI 902007: 90th percentile AQI 772008: 90th percentile AQI 672009: 90th percentile AQI 692010: 90th percentile AQI 772011: 90th percentile AQI 752012: 90th percentile AQI 682013: 90th percentile AQI 592014: 90th percentile AQI 662015: 90th percentile AQI 632016: 90th percentile AQI 562017: 90th percentile AQI 602018: 90th percentile AQI 672019: 90th percentile AQI 582020: 90th percentile AQI 592021: 90th percentile AQI 552022: 90th percentile AQI 612023: 90th percentile AQI 692024: 90th percentile AQI 612025: 90th percentile AQI 631982: Median AQI 451983: Median AQI 411984: Median AQI 401985: Median AQI 421986: Median AQI 421987: Median AQI 451988: Median AQI 431989: Median AQI 361990: Median AQI 391991: Median AQI 341992: Median AQI 371993: Median AQI 391994: Median AQI 341995: Median AQI 381996: Median AQI 381997: Median AQI 371998: Median AQI 401999: Median AQI 602000: Median AQI 582001: Median AQI 542002: Median AQI 522003: Median AQI 542004: Median AQI 542005: Median AQI 592006: Median AQI 582007: Median AQI 542008: Median AQI 522009: Median AQI 502010: Median AQI 532011: Median AQI 522012: Median AQI 482013: Median AQI 442014: Median AQI 482015: Median AQI 442016: Median AQI 422017: Median AQI 432018: Median AQI 472019: Median AQI 422020: Median AQI 402021: Median AQI 402022: Median AQI 462023: Median AQI 512024: Median AQI 462025: Median AQI 471982198719921997200220072012201720222025
  • 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)21158%
Ozone15242%
Nitrogen dioxide (NO₂)21%

Year-by-year data

Annual AQI summary by year
YearDays with AQIGoodModerateUnhealthy for Sensitive GroupsUnhealthyVery UnhealthyHazardousMedian AQI90th pct.Max AQIMain pollutant
202536522713710004763101PM2.5
202436622414101004661188PM2.5
202336418117940005169126PM2.5
20223622191430000466196PM2.5
20213552777620004055105PM2.5
2020366280860000405987Ozone
2019365269960000425884Ozone
201836520715710004767101PM2.5
201736524911420004360126PM2.5
20163662907510004256126Ozone
201536522613900004463100PM2.5
201436520615450004866122PM2.5
201336325610520004459115PM2.5
201236020515050004868129PM2.5
201136515919880005275143PM2.5
2010365137217101005377169PM2.5
200936518717170005069147PM2.5
200834215218730005267122PM2.5
2007365139208144005477179PM2.5
200636598244221005890174PM2.5
200535390239222005994154PM2.5
2004366138216102005475166PM2.5
2003365134215124005479192PM2.5
2002365158196110005271150PM2.5
2001365137199263005491172PM2.5
20003661062143880058105187PM2.5
1999365912313580060108179PM2.5
199836327862167004087192Ozone
199736428762132003777154Ozone
199636628663161003877159Ozone
1995359266583050038100172Ozone
19943653243092003458172Ozone
199336528468121003974161Ozone
19923663065280003767140Ozone
19913653144731003461164Ozone
199036528563152003984151Ozone
19893652906491103674204Ozone
19883662467629150043115187Ozone
19873652189142131045122206Ozone
1986365247813250042101200Ozone
198536526873203104287201Ozone
198436627763188004090185Ozone
198335526952259004197197Ozone
19822341355625117045136246Ozone

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 1982–2025 (EPA download page). EPA file dates: 2026-06-26. Imported into EnviroNearby November 5, 2026. How we use this data · Report a problem