EnviroNearby

Marion County, Florida air quality history

Daily Air Quality Index summaries from EPA monitors in Marion, Florida, 1998–2025.

67%
Good days in 2025
46
Median daily AQI, 2025
1
Days above 100 in 2025
364
Days with an AQI in 2025 (of 365)

In 2025, EPA reported a daily Air Quality Index (AQI) for Marion, Florida on 364 days. 245 of those days (67%) were in the Good range, and the median daily AQI was 46. That median is higher than the typical monitored county in Florida (median 41 across 38 counties), and higher than the typical monitored U.S. county (40). The main pollutant was fine particles (PM2.5) on 240 days. Across the years with fuller monitoring, the share of Good days fell: an average of 72% in 1998–2000 versus 62% 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%1998: Good 185 of 218 days1998: Moderate 22 of 218 days1998: Unhealthy for Sensitive Groups 9 of 218 days1998: Unhealthy 2 of 218 days19981999: Good 248 of 365 days1999: Moderate 97 of 365 days1999: Unhealthy for Sensitive Groups 18 of 365 days1999: Unhealthy 2 of 365 days2000: Good 227 of 366 days2000: Moderate 121 of 366 days2000: Unhealthy for Sensitive Groups 17 of 366 days2000: Unhealthy 1 of 366 days20002001: Good 259 of 365 days2001: Moderate 98 of 365 days2001: Unhealthy for Sensitive Groups 8 of 365 days2002: Good 272 of 365 days2002: Moderate 83 of 365 days2002: Unhealthy for Sensitive Groups 10 of 365 days20022003: Good 280 of 365 days2003: Moderate 79 of 365 days2003: Unhealthy for Sensitive Groups 5 of 365 days2003: Unhealthy 1 of 365 days2004: Good 249 of 353 days2004: Moderate 97 of 353 days2004: Unhealthy for Sensitive Groups 7 of 353 days20042005: Good 256 of 363 days2005: Moderate 99 of 363 days2005: Unhealthy for Sensitive Groups 8 of 363 days2006: Good 259 of 365 days2006: Moderate 98 of 365 days2006: Unhealthy for Sensitive Groups 8 of 365 days20062007: Good 269 of 365 days2007: Moderate 89 of 365 days2007: Unhealthy for Sensitive Groups 5 of 365 days2007: Unhealthy 2 of 365 days2008: Good 207 of 366 days2008: Moderate 155 of 366 days2008: Unhealthy for Sensitive Groups 4 of 366 days20082009: Good 223 of 365 days2009: Moderate 142 of 365 days2010: Good 195 of 365 days2010: Moderate 168 of 365 days2010: Unhealthy for Sensitive Groups 2 of 365 days20102011: Good 197 of 365 days2011: Moderate 164 of 365 days2011: Unhealthy for Sensitive Groups 4 of 365 days2012: Good 209 of 366 days2012: Moderate 157 of 366 days20122013: Good 238 of 365 days2013: Moderate 127 of 365 days2014: Good 224 of 365 days2014: Moderate 141 of 365 days20142015: Good 275 of 365 days2015: Moderate 90 of 365 days2016: Good 254 of 366 days2016: Moderate 111 of 366 days2016: Unhealthy for Sensitive Groups 1 of 366 days20162017: Good 250 of 351 days2017: Moderate 100 of 351 days2017: Unhealthy for Sensitive Groups 1 of 351 days2018: Good 273 of 365 days2018: Moderate 92 of 365 days20182019: Good 244 of 365 days2019: Moderate 121 of 365 days2020: Good 229 of 366 days2020: Moderate 137 of 366 days20202021: Good 257 of 365 days2021: Moderate 107 of 365 days2021: Unhealthy for Sensitive Groups 1 of 365 days2022: Good 259 of 363 days2022: Moderate 104 of 363 days20222023: Good 241 of 365 days2023: Moderate 124 of 365 days2024: Good 189 of 360 days2024: Moderate 170 of 360 days2024: Unhealthy for Sensitive Groups 1 of 360 days20242025: Good 245 of 364 days2025: Moderate 118 of 364 days2025: Unhealthy for Sensitive Groups 1 of 364 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 year0501001998: 90th percentile AQI 711999: 90th percentile AQI 842000: 90th percentile AQI 872001: 90th percentile AQI 682002: 90th percentile AQI 642003: 90th percentile AQI 592004: 90th percentile AQI 722005: 90th percentile AQI 712006: 90th percentile AQI 712007: 90th percentile AQI 632008: 90th percentile AQI 642009: 90th percentile AQI 602010: 90th percentile AQI 632011: 90th percentile AQI 672012: 90th percentile AQI 602013: 90th percentile AQI 592014: 90th percentile AQI 582015: 90th percentile AQI 572016: 90th percentile AQI 572017: 90th percentile AQI 582018: 90th percentile AQI 562019: 90th percentile AQI 582020: 90th percentile AQI 592021: 90th percentile AQI 572022: 90th percentile AQI 552023: 90th percentile AQI 572024: 90th percentile AQI 602025: 90th percentile AQI 571998: Median AQI 341999: Median AQI 432000: Median AQI 442001: Median AQI 422002: Median AQI 402003: Median AQI 392004: Median AQI 422005: Median AQI 402006: Median AQI 422007: Median AQI 432008: Median AQI 472009: Median AQI 472010: Median AQI 492011: Median AQI 482012: Median AQI 482013: Median AQI 442014: Median AQI 452015: Median AQI 402016: Median AQI 432017: Median AQI 432018: Median AQI 422019: Median AQI 442020: Median AQI 462021: Median AQI 422022: Median AQI 442023: Median AQI 452024: Median AQI 492025: Median AQI 46199820002002200420062008201020122014201620182020202220242025
  • 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)24066%
Ozone12434%

Year-by-year data

Annual AQI summary by year
YearDays with AQIGoodModerateUnhealthy for Sensitive GroupsUnhealthyVery UnhealthyHazardousMedian AQI90th pct.Max AQIMain pollutant
202536424511810004657101PM2.5
202436018917010004960101PM2.5
20233652411240000455799PM2.5
20223632591040000445593PM2.5
202136525710710004257101PM2.5
202036622913700004659100PM2.5
20193652441210000445888PM2.5
2018365273920000425690PM2.5
201735125010010004358101PM2.5
201636625411110004357105PM2.5
2015365275900000405771PM2.5
20143652241410000455897PM2.5
20133652381270000445990PM2.5
20123662091570000486084PM2.5
201136519716440004867119PM2.5
201036519516820004963112PM2.5
20093652231420000476090PM2.5
200836620715540004764108PM2.5
20073652698952004363169Ozone
20063652599880004271140Ozone
20053632569980004071136Ozone
20043532499770004272143Ozone
20033652807951003959156Ozone
200236527283100004064143Ozone
20013652599880004268133Ozone
2000366227121171004487151Ozone
199936524897182004384172Ozone
19982181852292003471166Ozone

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 Florida with a similar median AQI in 2025

All monitored counties in Florida

Source: U.S. EPA AirData, “Annual AQI by County” files for 1998–2025 (EPA download page). EPA file dates: 2026-06-26. Imported into EnviroNearby November 5, 2026. How we use this data · Report a problem