EnviroNearby

Bell County, Texas air quality history

Daily Air Quality Index summaries from EPA monitors in Bell, Texas, 1990–2025.

66%
Good days in 2025
45
Median daily AQI, 2025
4
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 Bell, Texas on 365 days. 241 of those days (66%) were in the Good range, and the median daily AQI was 45. 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 ozone on 236 days. Across the years with fuller monitoring, the share of Good days fell: an average of 85% in 2009–2011 versus 64% in 2023–2025.

Years with fewer than 120 monitored days (1991, 1992, 1993, 1994, 1995, 1996…) are shown in the table but left out of comparisons and trend statements.

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%1990: Good 16 of 16 days19901991: Good 56 of 57 days1991: Moderate 1 of 57 days1992: Good 59 of 60 days1992: Moderate 1 of 60 days19921993: Good 61 of 61 days1994: Good 57 of 57 days19941995: Good 57 of 58 days1995: Moderate 1 of 58 days1996: Good 56 of 56 days19962009: Good 181 of 201 days2009: Moderate 18 of 201 days2009: Unhealthy for Sensitive Groups 2 of 201 days2010: Good 316 of 362 days2010: Moderate 40 of 362 days2010: Unhealthy for Sensitive Groups 6 of 362 days20102011: Good 279 of 362 days2011: Moderate 71 of 362 days2011: Unhealthy for Sensitive Groups 12 of 362 days2012: Good 290 of 363 days2012: Moderate 64 of 363 days2012: Unhealthy for Sensitive Groups 8 of 363 days2012: Unhealthy 1 of 363 days20122013: Good 294 of 362 days2013: Moderate 64 of 362 days2013: Unhealthy for Sensitive Groups 4 of 362 days2014: Good 305 of 364 days2014: Moderate 57 of 364 days2014: Unhealthy for Sensitive Groups 2 of 364 days20142015: Good 309 of 365 days2015: Moderate 51 of 365 days2015: Unhealthy for Sensitive Groups 5 of 365 days2016: Good 331 of 365 days2016: Moderate 34 of 365 days20162017: Good 303 of 365 days2017: Moderate 57 of 365 days2017: Unhealthy for Sensitive Groups 5 of 365 days2018: Good 320 of 365 days2018: Moderate 40 of 365 days2018: Unhealthy for Sensitive Groups 5 of 365 days20182019: Good 237 of 365 days2019: Moderate 126 of 365 days2019: Unhealthy for Sensitive Groups 2 of 365 days2020: Good 236 of 366 days2020: Moderate 129 of 366 days2020: Unhealthy for Sensitive Groups 1 of 366 days20202021: Good 240 of 365 days2021: Moderate 122 of 365 days2021: Unhealthy for Sensitive Groups 3 of 365 days2022: Good 241 of 365 days2022: Moderate 121 of 365 days2022: Unhealthy for Sensitive Groups 3 of 365 days20222023: Good 231 of 365 days2023: Moderate 128 of 365 days2023: Unhealthy for Sensitive Groups 6 of 365 days2024: Good 226 of 366 days2024: Moderate 135 of 366 days2024: Unhealthy for Sensitive Groups 5 of 366 days20242025: Good 241 of 365 days2025: Moderate 120 of 365 days2025: Unhealthy for Sensitive Groups 4 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 year0501001990: 90th percentile AQI 191991: 90th percentile AQI 291992: 90th percentile AQI 281993: 90th percentile AQI 261994: 90th percentile AQI 231995: 90th percentile AQI 291996: 90th percentile AQI 242009: 90th percentile AQI 502010: 90th percentile AQI 582011: 90th percentile AQI 772012: 90th percentile AQI 712013: 90th percentile AQI 672014: 90th percentile AQI 642015: 90th percentile AQI 612016: 90th percentile AQI 502017: 90th percentile AQI 642018: 90th percentile AQI 542019: 90th percentile AQI 622020: 90th percentile AQI 632021: 90th percentile AQI 692022: 90th percentile AQI 732023: 90th percentile AQI 742024: 90th percentile AQI 702025: 90th percentile AQI 651990: Median AQI 151991: Median AQI 191992: Median AQI 151993: Median AQI 131994: Median AQI 131995: Median AQI 131996: Median AQI 142009: Median AQI 362010: Median AQI 372011: Median AQI 422012: Median AQI 402013: Median AQI 402014: Median AQI 392015: Median AQI 362016: Median AQI 382017: Median AQI 402018: Median AQI 362019: Median AQI 452020: Median AQI 442021: Median AQI 442022: Median AQI 462023: Median AQI 442024: Median AQI 462025: Median AQI 451990199219941996201020122014201620182020202220242025
  • 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
Ozone23665%
Fine particles (PM2.5)12935%

Year-by-year data

Annual AQI summary by year
YearDays with AQIGoodModerateUnhealthy for Sensitive GroupsUnhealthyVery UnhealthyHazardousMedian AQI90th pct.Max AQIMain pollutant
202536524112040004565140Ozone
202436622613550004670129Ozone
202336523112860004474133Ozone
202236524112130004673129Ozone
202136524012230004469122Ozone
202036623612910004463135Ozone
201936523712620004562105Ozone
20183653204050003654136Ozone
20173653035750004064133Ozone
20163653313400003850100Ozone
20153653095150003661133Ozone
20143643055720003964112Ozone
20133622946440004067115Ozone
20123632906481004071154Ozone
201136227971120004277136Ozone
20103623164060003758115Ozone
20092011811820003650112Ozone
1996565600000142441PM10
1995585710000132952PM10
1994575700000132336PM10
1993616100000132646PM10
1992605910000152855PM10
1991575610000192979PM10
1990161600000151935PM10

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 1990–2025 (EPA download page). EPA file dates: 2026-06-26. Imported into EnviroNearby November 5, 2026. How we use this data · Report a problem