EnviroNearby

Harrison County, Texas air quality history

Daily Air Quality Index summaries from EPA monitors in Harrison, Texas, 2001–2025.

64%
Good days in 2025
44
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 Harrison, Texas on 365 days. 235 of those days (64%) were in the Good range, and the median daily AQI was 44. That median is about the same as the typical monitored county in Texas (median 43.5 across 44 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 rose: an average of 59% in 2001–2003 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%2001: Good 88 of 156 days2001: Moderate 68 of 156 days20012002: Good 217 of 365 days2002: Moderate 115 of 365 days2002: Unhealthy for Sensitive Groups 28 of 365 days2002: Unhealthy 5 of 365 days2003: Good 222 of 363 days2003: Moderate 129 of 363 days2003: Unhealthy for Sensitive Groups 10 of 363 days2003: Unhealthy 2 of 363 days20032004: Good 249 of 363 days2004: Moderate 105 of 363 days2004: Unhealthy for Sensitive Groups 9 of 363 days2005: Good 122 of 362 days2005: Moderate 218 of 362 days2005: Unhealthy for Sensitive Groups 21 of 362 days2005: Unhealthy 1 of 362 days20052006: Good 140 of 365 days2006: Moderate 210 of 365 days2006: Unhealthy for Sensitive Groups 15 of 365 days2007: Good 153 of 365 days2007: Moderate 209 of 365 days2007: Unhealthy for Sensitive Groups 3 of 365 days20072008: Good 179 of 361 days2008: Moderate 180 of 361 days2008: Unhealthy for Sensitive Groups 2 of 361 days2009: Good 212 of 365 days2009: Moderate 151 of 365 days2009: Unhealthy for Sensitive Groups 2 of 365 days20092010: Good 161 of 365 days2010: Moderate 195 of 365 days2010: Unhealthy for Sensitive Groups 9 of 365 days2011: Good 139 of 365 days2011: Moderate 208 of 365 days2011: Unhealthy for Sensitive Groups 17 of 365 days2011: Very Unhealthy 1 of 365 days20112012: Good 159 of 366 days2012: Moderate 200 of 366 days2012: Unhealthy for Sensitive Groups 7 of 366 days2013: Good 213 of 365 days2013: Moderate 149 of 365 days2013: Unhealthy for Sensitive Groups 3 of 365 days20132014: Good 238 of 365 days2014: Moderate 126 of 365 days2014: Unhealthy for Sensitive Groups 1 of 365 days2015: Good 251 of 365 days2015: Moderate 114 of 365 days20152016: Good 265 of 366 days2016: Moderate 101 of 366 days2017: Good 218 of 363 days2017: Moderate 145 of 363 days20172018: Good 263 of 364 days2018: Moderate 100 of 364 days2018: Unhealthy for Sensitive Groups 1 of 364 days2019: Good 242 of 358 days2019: Moderate 116 of 358 days20192020: Good 264 of 363 days2020: Moderate 99 of 363 days2021: Good 205 of 362 days2021: Moderate 153 of 362 days2021: Unhealthy for Sensitive Groups 3 of 362 days2021: Unhealthy 1 of 362 days20212022: Good 164 of 328 days2022: Moderate 159 of 328 days2022: Unhealthy for Sensitive Groups 4 of 328 days2022: Unhealthy 1 of 328 days2023: Good 207 of 359 days2023: Moderate 151 of 359 days2023: Unhealthy for Sensitive Groups 1 of 359 days20232024: Good 233 of 365 days2024: Moderate 129 of 365 days2024: Unhealthy 1 of 365 days2024: Very Unhealthy 2 of 365 days2025: Good 235 of 365 days2025: Moderate 130 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 year0501002001: 90th percentile AQI 742002: 90th percentile AQI 972003: 90th percentile AQI 802004: 90th percentile AQI 712005: 90th percentile AQI 932006: 90th percentile AQI 842007: 90th percentile AQI 702008: 90th percentile AQI 672009: 90th percentile AQI 642010: 90th percentile AQI 712011: 90th percentile AQI 842012: 90th percentile AQI 692013: 90th percentile AQI 662014: 90th percentile AQI 612015: 90th percentile AQI 602016: 90th percentile AQI 562017: 90th percentile AQI 592018: 90th percentile AQI 592019: 90th percentile AQI 582020: 90th percentile AQI 572021: 90th percentile AQI 642022: 90th percentile AQI 642023: 90th percentile AQI 652024: 90th percentile AQI 612025: 90th percentile AQI 592001: Median AQI 442002: Median AQI 452003: Median AQI 462004: Median AQI 422005: Median AQI 552006: Median AQI 532007: Median AQI 532008: Median AQI 512009: Median AQI 462010: Median AQI 522011: Median AQI 542012: Median AQI 522013: Median AQI 472014: Median AQI 452015: Median AQI 422016: Median AQI 422017: Median AQI 462018: Median AQI 412019: Median AQI 442020: Median AQI 402021: Median AQI 472022: Median AQI 512023: Median AQI 472024: Median AQI 442025: Median AQI 442001200320052007200920112013201520172019202120232025
  • 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
202536523513000004459100PM2.5
202436523312901204461263PM2.5
202335920715110004765111PM2.5
202232816415941005164181PM2.5
202136220515331004764161PM2.5
20203632649900004057100PM2.5
20193582421160000445890PM2.5
201836426310010004159111PM2.5
201736321814500004659100PM2.5
20163662651010000425679PM2.5
20153652511140000426096PM2.5
201436523812610004561101PM2.5
201336521314930004766108PM2.5
201236615920070005269133PM2.5
2011365139208170105484215PM2.5
201036516119590005271126PM2.5
200936521215120004664112PM2.5
200836117918020005167108PM2.5
200736515320930005370132PM2.5
2006365140210150005384143PM2.5
2005362122218211005593154PM2.5
200436324910590004271150Ozone
2003363222129102004680169Ozone
2002365217115285004597161Ozone
200115688680000447492Ozone

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 2001–2025 (EPA download page). EPA file dates: 2026-06-26. Imported into EnviroNearby November 5, 2026. How we use this data · Report a problem