EnviroNearby

Lee County, Mississippi air quality history

Daily Air Quality Index summaries from EPA monitors in Lee, Mississippi, 1989–2025.

95%
Good days in 2025
38
Median daily AQI, 2025
0
Days above 100 in 2025
242
Days with an AQI in 2025 (of 365)

In 2025, EPA reported a daily Air Quality Index (AQI) for Lee, Mississippi on 242 days. 230 of those days (95%) were in the Good range, and the median daily AQI was 38. That median is lower than the typical monitored county in Mississippi (median 43 across 10 counties), and about the same as the typical monitored U.S. county (40). The main pollutant was ozone on 242 days. Across the years with fuller monitoring, the share of Good days rose: an average of 76% in 1989–1991 versus 90% in 2023–2025.

EPA did not report an AQI for every day of 2025 here (242 of 365 days). Figures describe monitored days only; seasonal monitoring (for example, ozone measured only in warmer months) can make a county look cleaner or dirtier than a full-year record would.

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%1989: Good 112 of 137 days1989: Moderate 24 of 137 days1989: Unhealthy for Sensitive Groups 1 of 137 days19891990: Good 166 of 267 days1990: Moderate 71 of 267 days1990: Unhealthy for Sensitive Groups 28 of 267 days1990: Unhealthy 2 of 267 days1991: Good 220 of 259 days1991: Moderate 34 of 259 days1991: Unhealthy for Sensitive Groups 5 of 259 days1992: Good 230 of 255 days1992: Moderate 21 of 255 days1992: Unhealthy for Sensitive Groups 4 of 255 days1993: Good 242 of 271 days1993: Moderate 28 of 271 days1993: Unhealthy for Sensitive Groups 1 of 271 days1994: Good 242 of 275 days1994: Moderate 29 of 275 days1994: Unhealthy for Sensitive Groups 3 of 275 days1994: Unhealthy 1 of 275 days19941995: Good 192 of 262 days1995: Moderate 57 of 262 days1995: Unhealthy for Sensitive Groups 13 of 262 days1996: Good 219 of 275 days1996: Moderate 52 of 275 days1996: Unhealthy for Sensitive Groups 4 of 275 days1997: Good 263 of 365 days1997: Moderate 82 of 365 days1997: Unhealthy for Sensitive Groups 19 of 365 days1997: Unhealthy 1 of 365 days1998: Good 125 of 238 days1998: Moderate 74 of 238 days1998: Unhealthy for Sensitive Groups 32 of 238 days1998: Unhealthy 7 of 238 days1999: Good 85 of 252 days1999: Moderate 112 of 252 days1999: Unhealthy for Sensitive Groups 47 of 252 days1999: Unhealthy 8 of 252 days19992000: Good 105 of 285 days2000: Moderate 137 of 285 days2000: Unhealthy for Sensitive Groups 40 of 285 days2000: Unhealthy 3 of 285 days2001: Good 141 of 283 days2001: Moderate 129 of 283 days2001: Unhealthy for Sensitive Groups 12 of 283 days2001: Unhealthy 1 of 283 days2002: Good 175 of 286 days2002: Moderate 99 of 286 days2002: Unhealthy for Sensitive Groups 11 of 286 days2002: Unhealthy 1 of 286 days2003: Good 172 of 322 days2003: Moderate 142 of 322 days2003: Unhealthy for Sensitive Groups 8 of 322 days2004: Good 113 of 366 days2004: Moderate 244 of 366 days2004: Unhealthy for Sensitive Groups 9 of 366 days20042005: Good 96 of 364 days2005: Moderate 246 of 364 days2005: Unhealthy for Sensitive Groups 22 of 364 days2006: Good 117 of 365 days2006: Moderate 237 of 365 days2006: Unhealthy for Sensitive Groups 11 of 365 days2007: Good 128 of 364 days2007: Moderate 224 of 364 days2007: Unhealthy for Sensitive Groups 11 of 364 days2007: Unhealthy 1 of 364 days2008: Good 155 of 362 days2008: Moderate 205 of 362 days2008: Unhealthy for Sensitive Groups 2 of 362 days2009: Good 157 of 345 days2009: Moderate 188 of 345 days20092010: Good 124 of 365 days2010: Moderate 239 of 365 days2010: Unhealthy for Sensitive Groups 2 of 365 days2011: Good 163 of 362 days2011: Moderate 199 of 362 days2012: Good 152 of 335 days2012: Moderate 182 of 335 days2012: Unhealthy for Sensitive Groups 1 of 335 days2013: Good 223 of 242 days2013: Moderate 18 of 242 days2013: Unhealthy for Sensitive Groups 1 of 242 days2014: Good 233 of 244 days2014: Moderate 11 of 244 days20142015: Good 228 of 235 days2015: Moderate 7 of 235 days2016: Good 224 of 238 days2016: Moderate 14 of 238 days2017: Good 217 of 225 days2017: Moderate 8 of 225 days2018: Good 226 of 243 days2018: Moderate 17 of 243 days2019: Good 222 of 241 days2019: Moderate 19 of 241 days20192020: Good 242 of 243 days2020: Moderate 1 of 243 days2021: Good 232 of 242 days2021: Moderate 10 of 242 days2022: Good 225 of 244 days2022: Moderate 19 of 244 days2023: Good 212 of 245 days2023: Moderate 31 of 245 days2023: Unhealthy for Sensitive Groups 2 of 245 days2024: Good 216 of 243 days2024: Moderate 27 of 243 days20242025: Good 230 of 242 days2025: Moderate 12 of 242 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 year0501001501989: 90th percentile AQI 611990: 90th percentile AQI 1051991: 90th percentile AQI 641992: 90th percentile AQI 501993: 90th percentile AQI 511994: 90th percentile AQI 611995: 90th percentile AQI 871996: 90th percentile AQI 641997: 90th percentile AQI 901998: 90th percentile AQI 1151999: 90th percentile AQI 1262000: 90th percentile AQI 1122001: 90th percentile AQI 872002: 90th percentile AQI 802003: 90th percentile AQI 772004: 90th percentile AQI 802005: 90th percentile AQI 882006: 90th percentile AQI 842007: 90th percentile AQI 842008: 90th percentile AQI 682009: 90th percentile AQI 652010: 90th percentile AQI 712011: 90th percentile AQI 652012: 90th percentile AQI 672013: 90th percentile AQI 492014: 90th percentile AQI 482015: 90th percentile AQI 472016: 90th percentile AQI 492017: 90th percentile AQI 482018: 90th percentile AQI 492019: 90th percentile AQI 492020: 90th percentile AQI 452021: 90th percentile AQI 462022: 90th percentile AQI 492023: 90th percentile AQI 542024: 90th percentile AQI 512025: 90th percentile AQI 481989: Median AQI 391990: Median AQI 451991: Median AQI 361992: Median AQI 341993: Median AQI 351994: Median AQI 341995: Median AQI 421996: Median AQI 401997: Median AQI 391998: Median AQI 501999: Median AQI 632000: Median AQI 602001: Median AQI 512002: Median AQI 462003: Median AQI 492004: Median AQI 562005: Median AQI 582006: Median AQI 572007: Median AQI 552008: Median AQI 522009: Median AQI 522010: Median AQI 542011: Median AQI 522012: Median AQI 522013: Median AQI 382014: Median AQI 372015: Median AQI 352016: Median AQI 392017: Median AQI 372018: Median AQI 362019: Median AQI 392020: Median AQI 352021: Median AQI 362022: Median AQI 402023: Median AQI 422024: Median AQI 412025: Median AQI 38198919941999200420092014201920242025
  • 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
Ozone242100%

Year-by-year data

Annual AQI summary by year
YearDays with AQIGoodModerateUnhealthy for Sensitive GroupsUnhealthyVery UnhealthyHazardousMedian AQI90th pct.Max AQIMain pollutant
2025242230120000384864Ozone
2024243216270000415187Ozone
20232452123120004254122Ozone
20222442251900004049100Ozone
2021242232100000364664Ozone
202024324210000354554Ozone
2019241222190000394984Ozone
2018243226170000364980Ozone
201722521780000374861Ozone
2016238224140000394980Ozone
201523522870000354774Ozone
2014244233110000374887Ozone
20132422231810003849101Ozone
201233515218210005267140PM2.5
20113621631990000526587PM2.5
201036512423920005471105PM2.5
20093451571880000526587PM2.5
200836215520520005268108PM2.5
2007364128224111005584153PM2.5
2006365117237110005784140PM2.5
200536496246220005888140PM2.5
200436611324490005680121PM2.5
200332217214280004977129Ozone
200228617599111004680169Ozone
2001283141129121005187161Ozone
20002851051374030060112164Ozone
1999252851124780063126182Ozone
1998238125743270050115177Ozone
199736526382191003990156Ozone
19962752195240004064147Ozone
199526219257130004287150Ozone
19942752422931003461166Ozone
19932712422810003551133Ozone
19922552302140003450112Ozone
19912592203450003664126Ozone
1990267166712820045105161Ozone
19891371122410003961105Ozone

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 Mississippi with a similar median AQI in 2025

All monitored counties in Mississippi

Source: U.S. EPA AirData, “Annual AQI by County” files for 1989–2025 (EPA download page). EPA file dates: 2026-06-26. Imported into EnviroNearby November 5, 2026. How we use this data · Report a problem