EnviroNearby

Johnson County, Texas air quality history

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

85%
Good days in 2025
37
Median daily AQI, 2025
1
Days above 100 in 2025
351
Days with an AQI in 2025 (of 365)

In 2025, EPA reported a daily Air Quality Index (AQI) for Johnson, Texas on 351 days. 300 of those days (85%) were in the Good range, and the median daily AQI was 37. 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 351 days. Across the years with fuller monitoring, the share of Good days rose: an average of 67% in 1990–2001 versus 82% 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%1990: Good 122 of 232 days1990: Moderate 74 of 232 days1990: Unhealthy for Sensitive Groups 33 of 232 days1990: Unhealthy 3 of 232 days19902000: Good 166 of 232 days2000: Moderate 46 of 232 days2000: Unhealthy for Sensitive Groups 18 of 232 days2000: Unhealthy 2 of 232 days2001: Good 275 of 360 days2001: Moderate 55 of 360 days2001: Unhealthy for Sensitive Groups 26 of 360 days2001: Unhealthy 4 of 360 days20012002: Good 278 of 364 days2002: Moderate 54 of 364 days2002: Unhealthy for Sensitive Groups 24 of 364 days2002: Unhealthy 7 of 364 days2002: Very Unhealthy 1 of 364 days2003: Good 268 of 365 days2003: Moderate 66 of 365 days2003: Unhealthy for Sensitive Groups 28 of 365 days2003: Unhealthy 3 of 365 days20032004: Good 277 of 364 days2004: Moderate 57 of 364 days2004: Unhealthy for Sensitive Groups 25 of 364 days2004: Unhealthy 5 of 364 days2005: Good 251 of 360 days2005: Moderate 75 of 360 days2005: Unhealthy for Sensitive Groups 27 of 360 days2005: Unhealthy 7 of 360 days20052006: Good 269 of 361 days2006: Moderate 69 of 361 days2006: Unhealthy for Sensitive Groups 20 of 361 days2006: Unhealthy 3 of 361 days2007: Good 312 of 359 days2007: Moderate 35 of 359 days2007: Unhealthy for Sensitive Groups 8 of 359 days2007: Unhealthy 4 of 359 days20072008: Good 293 of 365 days2008: Moderate 56 of 365 days2008: Unhealthy for Sensitive Groups 14 of 365 days2008: Unhealthy 2 of 365 days2009: Good 291 of 362 days2009: Moderate 57 of 362 days2009: Unhealthy for Sensitive Groups 13 of 362 days2009: Unhealthy 1 of 362 days20092010: Good 310 of 355 days2010: Moderate 38 of 355 days2010: Unhealthy for Sensitive Groups 7 of 355 days2011: Good 284 of 359 days2011: Moderate 58 of 359 days2011: Unhealthy for Sensitive Groups 16 of 359 days2011: Unhealthy 1 of 359 days20112012: Good 283 of 353 days2012: Moderate 55 of 353 days2012: Unhealthy for Sensitive Groups 14 of 353 days2012: Very Unhealthy 1 of 353 days2013: Good 289 of 352 days2013: Moderate 52 of 352 days2013: Unhealthy for Sensitive Groups 11 of 352 days20132014: Good 307 of 361 days2014: Moderate 50 of 361 days2014: Unhealthy for Sensitive Groups 4 of 361 days2015: Good 300 of 361 days2015: Moderate 55 of 361 days2015: Unhealthy for Sensitive Groups 5 of 361 days2015: Unhealthy 1 of 361 days20152016: Good 300 of 357 days2016: Moderate 53 of 357 days2016: Unhealthy for Sensitive Groups 4 of 357 days2017: Good 293 of 362 days2017: Moderate 61 of 362 days2017: Unhealthy for Sensitive Groups 8 of 362 days20172018: Good 302 of 354 days2018: Moderate 44 of 354 days2018: Unhealthy for Sensitive Groups 7 of 354 days2018: Unhealthy 1 of 354 days2019: Good 298 of 352 days2019: Moderate 47 of 352 days2019: Unhealthy for Sensitive Groups 7 of 352 days20192020: Good 320 of 349 days2020: Moderate 27 of 349 days2020: Unhealthy for Sensitive Groups 2 of 349 days2021: Good 311 of 363 days2021: Moderate 46 of 363 days2021: Unhealthy for Sensitive Groups 6 of 363 days20212022: Good 281 of 362 days2022: Moderate 67 of 362 days2022: Unhealthy for Sensitive Groups 13 of 362 days2022: Unhealthy 1 of 362 days2023: Good 283 of 362 days2023: Moderate 71 of 362 days2023: Unhealthy for Sensitive Groups 8 of 362 days20232024: Good 286 of 350 days2024: Moderate 54 of 350 days2024: Unhealthy for Sensitive Groups 10 of 350 days2025: Good 300 of 351 days2025: Moderate 50 of 351 days2025: Unhealthy for Sensitive Groups 1 of 351 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 year0501001501990: 90th percentile AQI 1152000: 90th percentile AQI 972001: 90th percentile AQI 932002: 90th percentile AQI 932003: 90th percentile AQI 932004: 90th percentile AQI 932005: 90th percentile AQI 1002006: 90th percentile AQI 872007: 90th percentile AQI 582008: 90th percentile AQI 712009: 90th percentile AQI 742010: 90th percentile AQI 582011: 90th percentile AQI 772012: 90th percentile AQI 772013: 90th percentile AQI 712014: 90th percentile AQI 612015: 90th percentile AQI 642016: 90th percentile AQI 642017: 90th percentile AQI 712018: 90th percentile AQI 612019: 90th percentile AQI 612020: 90th percentile AQI 502021: 90th percentile AQI 612022: 90th percentile AQI 742023: 90th percentile AQI 742024: 90th percentile AQI 672025: 90th percentile AQI 581990: Median AQI 482000: Median AQI 352001: Median AQI 392002: Median AQI 382003: Median AQI 412004: Median AQI 382005: Median AQI 402006: Median AQI 392007: Median AQI 322008: Median AQI 382009: Median AQI 372010: Median AQI 362011: Median AQI 382012: Median AQI 382013: Median AQI 372014: Median AQI 362015: Median AQI 352016: Median AQI 402017: Median AQI 412018: Median AQI 352019: Median AQI 382020: Median AQI 342021: Median AQI 372022: Median AQI 412023: Median AQI 382024: Median AQI 392025: Median AQI 3719902001200320052007200920112013201520172019202120232025
  • 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
Ozone351100%

Year-by-year data

Annual AQI summary by year
YearDays with AQIGoodModerateUnhealthy for Sensitive GroupsUnhealthyVery UnhealthyHazardousMedian AQI90th pct.Max AQIMain pollutant
20253513005010003758101Ozone
202435028654100003967129Ozone
20233622837180003874126Ozone
202236228167131004174156Ozone
20213633114660003761136Ozone
20203493202720003450105Ozone
20193522984770003861143Ozone
20183543024471003561156Ozone
20173622936180004171147Ozone
20163573005340004064150Ozone
20153613005551003564156Ozone
20143613075040003661129Ozone
201335228952110003771143Ozone
201235328355140103877203Ozone
201135928458161003877161Ozone
20103553103870003658140Ozone
200936229157131003774154Ozone
200836529356142003871169Ozone
20073593123584003258169Ozone
200636126969203003987182Ozone
2005360251752770040100172Ozone
200436427757255003893190Ozone
200336526866283004193154Ozone
200236427854247103893209Ozone
200136027555264003993174Ozone
200023216646182003597172Ozone
1990232122743330048115174Ozone

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