EnviroNearby

Polk County, Texas air quality history

Daily Air Quality Index summaries from EPA monitors in Polk, Texas, 2004–2025.

95%
Good days in 2025
33
Median daily AQI, 2025
1
Days above 100 in 2025
344
Days with an AQI in 2025 (of 365)

In 2025, EPA reported a daily Air Quality Index (AQI) for Polk, Texas on 344 days. 326 of those days (95%) were in the Good range, and the median daily AQI was 33. That median is lower than the typical monitored county in Texas (median 43.5 across 44 counties), and lower than the typical monitored U.S. county (40). The main pollutant was ozone on 344 days. Across the years with fuller monitoring, the share of Good days rose: an average of 84% in 2004–2006 versus 94% 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%2004: Good 199 of 248 days2004: Moderate 42 of 248 days2004: Unhealthy for Sensitive Groups 7 of 248 days20042005: Good 263 of 316 days2005: Moderate 46 of 316 days2005: Unhealthy for Sensitive Groups 7 of 316 days2006: Good 301 of 338 days2006: Moderate 34 of 338 days2006: Unhealthy for Sensitive Groups 3 of 338 days20062007: Good 231 of 248 days2007: Moderate 15 of 248 days2007: Unhealthy for Sensitive Groups 2 of 248 days2008: Good 294 of 330 days2008: Moderate 32 of 330 days2008: Unhealthy for Sensitive Groups 4 of 330 days20082009: Good 296 of 344 days2009: Moderate 45 of 344 days2009: Unhealthy for Sensitive Groups 3 of 344 days2010: Good 265 of 317 days2010: Moderate 47 of 317 days2010: Unhealthy for Sensitive Groups 5 of 317 days20102011: Good 264 of 328 days2011: Moderate 54 of 328 days2011: Unhealthy for Sensitive Groups 10 of 328 days2012: Good 246 of 281 days2012: Moderate 34 of 281 days2012: Unhealthy for Sensitive Groups 1 of 281 days20122013: Good 251 of 273 days2013: Moderate 21 of 273 days2013: Unhealthy for Sensitive Groups 1 of 273 days2014: Good 316 of 330 days2014: Moderate 12 of 330 days2014: Unhealthy for Sensitive Groups 2 of 330 days20142015: Good 310 of 327 days2015: Moderate 17 of 327 days2016: Good 341 of 346 days2016: Moderate 5 of 346 days20162017: Good 333 of 342 days2017: Moderate 9 of 342 days2018: Good 347 of 365 days2018: Moderate 18 of 365 days20182019: Good 334 of 344 days2019: Moderate 10 of 344 days2020: Good 351 of 360 days2020: Moderate 9 of 360 days20202021: Good 349 of 353 days2021: Moderate 4 of 353 days2022: Good 313 of 328 days2022: Moderate 15 of 328 days20222023: Good 324 of 356 days2023: Moderate 32 of 356 days2024: Good 338 of 350 days2024: Moderate 12 of 350 days20242025: Good 326 of 344 days2025: Moderate 17 of 344 days2025: Unhealthy for Sensitive Groups 1 of 344 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 year0501002004: 90th percentile AQI 672005: 90th percentile AQI 642006: 90th percentile AQI 542007: 90th percentile AQI 492008: 90th percentile AQI 582009: 90th percentile AQI 582010: 90th percentile AQI 642011: 90th percentile AQI 742012: 90th percentile AQI 512013: 90th percentile AQI 502014: 90th percentile AQI 452015: 90th percentile AQI 462016: 90th percentile AQI 442017: 90th percentile AQI 442018: 90th percentile AQI 452019: 90th percentile AQI 442020: 90th percentile AQI 432021: 90th percentile AQI 432022: 90th percentile AQI 462023: 90th percentile AQI 502024: 90th percentile AQI 452025: 90th percentile AQI 482004: Median AQI 382005: Median AQI 392006: Median AQI 332007: Median AQI 312008: Median AQI 342009: Median AQI 382010: Median AQI 392011: Median AQI 392012: Median AQI 372013: Median AQI 352014: Median AQI 322015: Median AQI 312016: Median AQI 322017: Median AQI 312018: Median AQI 312019: Median AQI 312020: Median AQI 312021: Median AQI 302022: Median AQI 322023: Median AQI 372024: Median AQI 332025: Median AQI 33200420062008201020122014201620182020202220242025
  • 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
Ozone344100%

Year-by-year data

Annual AQI summary by year
YearDays with AQIGoodModerateUnhealthy for Sensitive GroupsUnhealthyVery UnhealthyHazardousMedian AQI90th pct.Max AQIMain pollutant
20253443261710003348105Ozone
2024350338120000334593Ozone
20233563243200003750100Ozone
2022328313150000324697Ozone
202135334940000304361Ozone
202036035190000314371Ozone
2019344334100000314474Ozone
2018365347180000314597Ozone
2017342333900003144100Ozone
201634634150000324477Ozone
2015327310170000314693Ozone
20143303161220003245112Ozone
20132732512110003550101Ozone
20122812463410003751119Ozone
201132826454100003974129Ozone
20103172654750003964150Ozone
20093442964530003858126Ozone
20083302943240003458129Ozone
20072482311520003149108Ozone
20063383013430003354143Ozone
20053162634670003964115Ozone
20042481994270003867140Ozone

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 Texas with a similar median AQI in 2025

All monitored counties in Texas

Source: U.S. EPA AirData, “Annual AQI by County” files for 2004–2025 (EPA download page). EPA file dates: 2026-06-26. Imported into EnviroNearby November 5, 2026. How we use this data · Report a problem