Lake Charles, LA Air Quality

EPA monitor data through 2025 · Updated September 02, 2026 · Methods

In 2025, Lake Charles, LA recorded 3 days above an Air Quality Index of 100, the level at which EPA begins warning sensitive groups, out of 365 days with monitoring data. The rest of the year was 227 Good days and 135 Moderate days. Most of the bad days were driven by ozone. Under the AQI rules that applied before 2013, the same air would have scored 0 days. Since 2000, unhealthy days are 100% lower on a consistent definition.

Unhealthy days, 2025
3
AQI above 100
Same air, pre-2013 rules
0
for comparison with older reports
Good-air days
227
AQI 50 or below
Days monitored
365
full year

Unhealthy days by year, scored two ways

EPA changed what an AQI of 100 means in 2013 and again in 2015, so a count published before those changes is not comparable to one published after. Each panel below applies a single fixed rulebook to every year, so each is internally consistent. Why this matters.

Scored by today's rules

Lake Charles, LA: days above AQI 100 by year, current rules 0 10 20 30 40 2000 2005 2010 2015 2020 2025 2000: 44 days 2001: 16 days 2002: 8 days 2003: 18 days 2004: 13 days 2005: 25 days 2006: 17 days 2007: 9 days 2008: 7 days 2009: 10 days 2010: 9 days 2011: 9 days 2012: 6 days 2013: 3 days 2014: 3 days 2015: 4 days 2016: 1 days 2017: 3 days 2018: 6 days 2019: 0 days 2020: 1 days 2021: 1 days 2022: 0 days 2023: 5 days 2024: 3 days 2025: 3 days

Scored by the pre-2013 rules

Lake Charles, LA: days above AQI 100 by year, pre-2013 rules 0 10 20 30 40 2000 2005 2010 2015 2020 2025 2000: 25 days 2001: 10 days 2002: 4 days 2003: 14 days 2004: 9 days 2005: 18 days 2006: 10 days 2007: 5 days 2008: 2 days 2009: 8 days 2010: 5 days 2011: 3 days 2012: 1 days 2013: 0 days 2014: 1 days 2015: 2 days 2016: 0 days 2017: 0 days 2018: 0 days 2019: 0 days 2020: 1 days 2021: 1 days 2022: 0 days 2023: 1 days 2024: 2 days 2025: 0 days

Ozone since 1990

The index counts above only start in 2000, because nationwide fine-particle monitoring did not exist before 1999 and an index without it would measure the monitoring network rather than the air. Ozone does have a 35-year record. This is Lake Charles, LA's, from EPA's long-running trend monitors: 85 ppb in 1990 to 66 ppb in 2024, 22% lower.

Peak ozone, 1990 to 2024

Lake Charles, LA: peak ozone by year since 1990, ppb 0 20 40 60 80 100 1994 2004 2014 2024 1990: 85 ppb 1991: 87 ppb 1992: 73 ppb 1993: 77 ppb 1994: 75 ppb 1995: 84 ppb 1996: 77 ppb 1997: 85 ppb 1998: 90 ppb 1999: 73 ppb 2000: 82 ppb 2001: 78 ppb 2002: 74 ppb 2003: 84 ppb 2004: 82 ppb 2005: 85 ppb 2006: 80 ppb 2007: 78 ppb 2008: 69 ppb 2009: 77 ppb 2010: 78 ppb 2011: 74 ppb 2012: 72 ppb 2013: 65 ppb 2014: 67 ppb 2015: 72 ppb 2016: 65 ppb 2017: 62 ppb 2018: 69 ppb 2019: 65 ppb 2020: 58 ppb 2021: 62 ppb 2022: 65 ppb 2023: 70 ppb 2024: 66 ppb 70 ppb standard
Annual fourth-highest daily maximum 8-hour ozone, parts per billion, averaged across 1 long-running monitor in the area. The dashed line is the current standard, 70 ppb. Holding the monitor set still is what makes a 35-year comparison meaningful, and it is also why these values differ from the design value used for compliance. Source: EPA air quality statistics by city.

What 2025 looked like

Air quality categoryDaysShare of days with an AQI
Good22762%
Moderate13537%
Unhealthy for sensitive groups31%
Unhealthy or worse00%

Median AQI 47 · 90th-percentile AQI 61 · worst day 108. Scored under current rules, out of 365 days with an AQI.

What drove the unhealthy days

Of the 3 days above 100 in 2025, 3 were driven by ozone and 0 by fine particles. The two behave differently. Ozone peaks on hot sunny afternoons; fine particles now spike mainly with wildfire smoke. In the eastern United States, ozone has stopped responding to emission cuts: nitrogen oxide emissions kept falling after 2014 and ambient ozone barely moved.

The unhealthy days in 2025

Every day the index passed 100, what it reached, and which pollutant drove it. 3 of these 3 would not have counted as unhealthy under the pre-2013 rules.

DatePeak AQIDriven byPre-2013 score
Aug 5108Ozone 93 (not unhealthy)
Sep 4108Ozone 93 (not unhealthy)
Oct 13105Ozone 90 (not unhealthy)

Statewide context

Lake Charles, LA sits in Louisiana.

Days in each air quality category, by year

How many days fell in each AQI category, for every year with an AQI on record. Categories are scored under EPA's current breakpoints. A year with fewer than 300 days is marked, because a short year lowers every count for reasons that have nothing to do with the air.

YearGoodModerate Unhealthy for sensitive groupsUnhealthy or worse Days with an AQI
2000 12719536 8366
2001 15019913 3365
2002 1961618 0365
2003 12322415 3365
2004 17018312 1366
2005 10821522 3348
2006 13321515 2365
2007 1601969 0365
2008 1611987 0366
2009 1791768 2365
2010 1472099 0365
2011 1691879 0365
2012 1991616 0366
2013 1751873 0365
2014 2011613 0365
2015 1492123 1365
2016 1262391 0366
2017 1182443 0365
2018 1452146 0365
2019 1312340 0365
2020 1801691 0350
2021 1711930 1365
2022 1671980 0365
2023 1392215 0365
2024 1941693 0366
2025 2271353 0365

Good is AQI 0–50, Moderate 51–100, Unhealthy for sensitive groups 101–150. “Unhealthy or worse” combines the Unhealthy, Very Unhealthy and Hazardous categories, which are shown together because most areas record too few of each to report separately. The four columns sum to the last one by construction. These counts exclude sulphur dioxide, following EPA, which drops SO₂ from county and metro summaries because it is too localized to describe a whole area.

The full series

The same years scored two ways, with the pollutant that drove the days above 100. EPA's files record which pollutant set each day's AQI; they do not attribute days to wildfire smoke, so no column here claims to.

YearUnhealthy days, current rulesOf which ozone Of which fine particlesPre-2013 rulesDays monitored
200044 35 9 25366
200116 14 2 10365
20028 6 2 4365
200318 18 0 14365
200413 12 1 9366
200525 24 1 18348
200617 14 3 10365
20079 9 0 5365
20087 7 0 2366
200910 10 0 8365
20109 9 0 5365
20119 9 0 3365
20126 6 0 1366
20133 3 0 0365
20143 2 1 1365
20154 4 0 2365
20161 1 0 0366
20173 2 1 0365
20186 3 3 0365
20190 0 0 0365
20201 0 1 1352
20211 1 0 1365
20220 0 0 0365
20235 4 1 1365
20243 2 1 2366
20253 3 0 0365

Sources