EnviroNearby

Ouachita Parish, Louisiana air quality history

Daily Air Quality Index summaries from EPA monitors in Ouachita, Louisiana, 1981–2025.

62%
Good days in 2025
45
Median daily AQI, 2025
0
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 Ouachita, Louisiana on 365 days. 227 of those days (62%) 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 243 days. Across the years with fuller monitoring, the share of Good days fell: an average of 81% in 1981–1983 versus 74% in 2023–2025.

Years with fewer than 120 monitored days (1989, 1990, 1991) 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.

Share of monitored days in each AQI category, by year0%25%50%75%100%1981: Good 130 of 206 days1981: Moderate 45 of 206 days1981: Unhealthy for Sensitive Groups 24 of 206 days1981: Unhealthy 7 of 206 days19811982: Good 279 of 306 days1982: Moderate 27 of 306 days1983: Good 288 of 329 days1983: Moderate 34 of 329 days1983: Unhealthy for Sensitive Groups 7 of 329 days1984: Good 322 of 357 days1984: Moderate 33 of 357 days1984: Unhealthy for Sensitive Groups 2 of 357 days1985: Good 289 of 358 days1985: Moderate 52 of 358 days1985: Unhealthy for Sensitive Groups 15 of 358 days1985: Unhealthy 2 of 358 days1986: Good 277 of 355 days1986: Moderate 64 of 355 days1986: Unhealthy for Sensitive Groups 14 of 355 days19861987: Good 252 of 351 days1987: Moderate 68 of 351 days1987: Unhealthy for Sensitive Groups 28 of 351 days1987: Unhealthy 3 of 351 days1988: Good 255 of 355 days1988: Moderate 61 of 355 days1988: Unhealthy for Sensitive Groups 33 of 355 days1988: Unhealthy 6 of 355 days1989: Good 24 of 26 days1989: Moderate 2 of 26 days1990: Good 55 of 59 days1990: Moderate 4 of 59 days1991: Good 56 of 59 days1991: Moderate 3 of 59 days19911992: Good 302 of 362 days1992: Moderate 54 of 362 days1992: Unhealthy for Sensitive Groups 6 of 362 days1993: Good 296 of 361 days1993: Moderate 58 of 361 days1993: Unhealthy for Sensitive Groups 7 of 361 days1994: Good 295 of 360 days1994: Moderate 53 of 360 days1994: Unhealthy for Sensitive Groups 11 of 360 days1994: Unhealthy 1 of 360 days1995: Good 264 of 358 days1995: Moderate 65 of 358 days1995: Unhealthy for Sensitive Groups 28 of 358 days1995: Unhealthy 1 of 358 days1996: Good 189 of 259 days1996: Moderate 62 of 259 days1996: Unhealthy for Sensitive Groups 8 of 259 days19961997: Good 286 of 362 days1997: Moderate 68 of 362 days1997: Unhealthy for Sensitive Groups 8 of 362 days1998: Good 280 of 359 days1998: Moderate 68 of 359 days1998: Unhealthy for Sensitive Groups 11 of 359 days1999: Good 201 of 363 days1999: Moderate 135 of 363 days1999: Unhealthy for Sensitive Groups 26 of 363 days1999: Unhealthy 1 of 363 days2000: Good 221 of 365 days2000: Moderate 110 of 365 days2000: Unhealthy for Sensitive Groups 32 of 365 days2000: Unhealthy 2 of 365 days2001: Good 237 of 360 days2001: Moderate 107 of 360 days2001: Unhealthy for Sensitive Groups 16 of 360 days20012002: Good 264 of 361 days2002: Moderate 89 of 361 days2002: Unhealthy for Sensitive Groups 8 of 361 days2003: Good 229 of 362 days2003: Moderate 117 of 362 days2003: Unhealthy for Sensitive Groups 15 of 362 days2003: Unhealthy 1 of 362 days2004: Good 251 of 352 days2004: Moderate 95 of 352 days2004: Unhealthy for Sensitive Groups 6 of 352 days2005: Good 206 of 362 days2005: Moderate 128 of 362 days2005: Unhealthy for Sensitive Groups 27 of 362 days2005: Unhealthy 1 of 362 days2006: Good 249 of 361 days2006: Moderate 102 of 361 days2006: Unhealthy for Sensitive Groups 10 of 361 days20062007: Good 267 of 356 days2007: Moderate 88 of 356 days2007: Unhealthy for Sensitive Groups 1 of 356 days2008: Good 304 of 360 days2008: Moderate 56 of 360 days2009: Good 292 of 360 days2009: Moderate 68 of 360 days2010: Good 212 of 363 days2010: Moderate 148 of 363 days2010: Unhealthy for Sensitive Groups 3 of 363 days2011: Good 134 of 365 days2011: Moderate 231 of 365 days20112012: Good 71 of 366 days2012: Moderate 295 of 366 days2013: Good 44 of 365 days2013: Moderate 320 of 365 days2013: Unhealthy for Sensitive Groups 1 of 365 days2014: Good 190 of 364 days2014: Moderate 174 of 364 days2015: Good 286 of 335 days2015: Moderate 49 of 335 days2016: Good 288 of 344 days2016: Moderate 56 of 344 days20162017: Good 308 of 361 days2017: Moderate 53 of 361 days2018: Good 323 of 363 days2018: Moderate 40 of 363 days2019: Good 310 of 363 days2019: Moderate 53 of 363 days2020: Good 324 of 362 days2020: Moderate 37 of 362 days2020: Unhealthy for Sensitive Groups 1 of 362 days2021: Good 318 of 349 days2021: Moderate 31 of 349 days20212022: Good 309 of 359 days2022: Moderate 49 of 359 days2022: Unhealthy for Sensitive Groups 1 of 359 days2023: Good 283 of 358 days2023: Moderate 75 of 358 days2024: Good 292 of 366 days2024: Moderate 74 of 366 days2025: Good 227 of 365 days2025: Moderate 138 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 year0501001501981: 90th percentile AQI 1261982: 90th percentile AQI 491983: 90th percentile AQI 581984: 90th percentile AQI 501985: 90th percentile AQI 711986: 90th percentile AQI 871987: 90th percentile AQI 1001988: 90th percentile AQI 1081989: 90th percentile AQI 421990: 90th percentile AQI 481991: 90th percentile AQI 481992: 90th percentile AQI 581993: 90th percentile AQI 671994: 90th percentile AQI 711995: 90th percentile AQI 971996: 90th percentile AQI 741997: 90th percentile AQI 771998: 90th percentile AQI 841999: 90th percentile AQI 932000: 90th percentile AQI 1002001: 90th percentile AQI 762002: 90th percentile AQI 712003: 90th percentile AQI 772004: 90th percentile AQI 682005: 90th percentile AQI 972006: 90th percentile AQI 742007: 90th percentile AQI 632008: 90th percentile AQI 552009: 90th percentile AQI 562010: 90th percentile AQI 682011: 90th percentile AQI 682012: 90th percentile AQI 692013: 90th percentile AQI 762014: 90th percentile AQI 642015: 90th percentile AQI 542016: 90th percentile AQI 542017: 90th percentile AQI 532018: 90th percentile AQI 512019: 90th percentile AQI 522020: 90th percentile AQI 512021: 90th percentile AQI 502022: 90th percentile AQI 532023: 90th percentile AQI 582024: 90th percentile AQI 572025: 90th percentile AQI 581981: Median AQI 431982: Median AQI 311983: Median AQI 301984: Median AQI 281985: Median AQI 351986: Median AQI 351987: Median AQI 381988: Median AQI 401989: Median AQI 221990: Median AQI 251991: Median AQI 191992: Median AQI 371993: Median AQI 351994: Median AQI 381995: Median AQI 391996: Median AQI 421997: Median AQI 351998: Median AQI 361999: Median AQI 462000: Median AQI 442001: Median AQI 422002: Median AQI 392003: Median AQI 442004: Median AQI 402005: Median AQI 462006: Median AQI 432007: Median AQI 382008: Median AQI 342009: Median AQI 352010: Median AQI 452011: Median AQI 542012: Median AQI 572013: Median AQI 612014: Median AQI 472015: Median AQI 332016: Median AQI 372017: Median AQI 352018: Median AQI 342019: Median AQI 362020: Median AQI 342021: Median AQI 352022: Median AQI 382023: Median AQI 382024: Median AQI 412025: Median AQI 451981198619911996200120062011201620212025
  • 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)24367%
Ozone12233%

Year-by-year data

Annual AQI summary by year
YearDays with AQIGoodModerateUnhealthy for Sensitive GroupsUnhealthyVery UnhealthyHazardousMedian AQI90th pct.Max AQIMain pollutant
20253652271380000455880PM2.5
2024366292740000415797Ozone
20233582837500003858100Ozone
20223593094910003853105Ozone
2021349318310000355087Ozone
20203623243710003451111Ozone
2019363310530000365271Ozone
20183633234000003451100Ozone
2017361308530000355383Ozone
2016344288560000375475Ozone
2015335286490000335474Ozone
20143641901740000476488PM2.5
20133654432010006176120PM2.5
2012366712950000576992PM2.5
201136513423100005468100PM2.5
201036321214830004568101Ozone
2009360292680000355697Ozone
2008360304560000345575Ozone
20073562678810003863101Ozone
2006361249102100004374126Ozone
2005362206128271004697154Ozone
20043522519560004068122Ozone
2003362229117151004477154Ozone
20023612648980003971150Ozone
2001360237107160004276140Ozone
20003652211103220044100174Ozone
1999363201135261004693161Ozone
199835928068110003684136Ozone
19973622866880003577129Ozone
19962591896280004274126Ozone
199535826465281003997151Ozone
199436029553111003871182Ozone
19933612965870003567140Ozone
19923623025460003758122Ozone
1991595630000194859PM10
1990595540000254867PM10
1989262420000224255PM10
1988355255613360040108177Ozone
1987351252682830038100154Ozone
198635527764140003587136Ozone
198535828952152003571154Ozone
19843573223320002850115Ozone
19833292883470003058129Ozone
19823062792700003149100Ozone
1981206130452470043126169Ozone

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 1981–2025 (EPA download page). EPA file dates: 2026-06-26. Imported into EnviroNearby November 5, 2026. How we use this data · Report a problem