EnviroNearby

Chambers County, Texas air quality history

Daily Air Quality Index summaries from EPA monitors in Chambers, Texas, 1981–1987.

65%
Good days in 1986
42
Median daily AQI, 1986
72
Days above 100 in 1986
365
Days with an AQI in 1986 (of 365)

In 1986, EPA reported a daily Air Quality Index (AQI) for Chambers, Texas on 365 days. 236 of those days (65%) were in the Good range, and the median daily AQI was 42. That median is higher than the typical monitored county in Texas (median 39.5 across 16 counties), and higher than the typical monitored U.S. county (39). The main pollutant was ozone on 365 days. Across the years with fuller monitoring, the share of Good days fell: an average of 72% in 1981–1983 versus 66% in 1984–1986.

The most recent year with data for this county is 1987; EPA's files for 1988–2025 contain no row for it, which usually means its monitors stopped reporting.

Years with fewer than 120 monitored days (1987) 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%1981: Good 93 of 140 days1981: Moderate 27 of 140 days1981: Unhealthy for Sensitive Groups 10 of 140 days1981: Unhealthy 6 of 140 days1981: Very Unhealthy 4 of 140 days19811982: Good 259 of 358 days1982: Moderate 62 of 358 days1982: Unhealthy for Sensitive Groups 19 of 358 days1982: Unhealthy 15 of 358 days1982: Very Unhealthy 3 of 358 days19821983: Good 276 of 353 days1983: Moderate 51 of 353 days1983: Unhealthy for Sensitive Groups 20 of 353 days1983: Unhealthy 6 of 353 days19831984: Good 252 of 362 days1984: Moderate 63 of 362 days1984: Unhealthy for Sensitive Groups 33 of 362 days1984: Unhealthy 11 of 362 days1984: Very Unhealthy 3 of 362 days19841985: Good 232 of 365 days1985: Moderate 53 of 365 days1985: Unhealthy for Sensitive Groups 41 of 365 days1985: Unhealthy 24 of 365 days1985: Very Unhealthy 15 of 365 days19851986: Good 236 of 365 days1986: Moderate 57 of 365 days1986: Unhealthy for Sensitive Groups 39 of 365 days1986: Unhealthy 24 of 365 days1986: Very Unhealthy 9 of 365 days19861987: Good 58 of 59 days1987: Moderate 1 of 59 days1987
  • 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 year0501001502001981: 90th percentile AQI 1331982: 90th percentile AQI 1051983: 90th percentile AQI 841984: 90th percentile AQI 1121985: 90th percentile AQI 1591986: 90th percentile AQI 1471987: 90th percentile AQI 421981: Median AQI 431982: Median AQI 391983: Median AQI 371984: Median AQI 401985: Median AQI 431986: Median AQI 421987: Median AQI 301981198219831984198519861987
  • Median daily AQI
  • 90th-percentile daily AQI

Main pollutant by day, 1986

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
Ozone365100%

Year-by-year data

Annual AQI summary by year
YearDays with AQIGoodModerateUnhealthy for Sensitive GroupsUnhealthyVery UnhealthyHazardousMedian AQI90th pct.Max AQIMain pollutant
1987595810000304267Ozone
19863652365739249042147235Ozone
198536523253412415043159244Ozone
19843622526333113040112218Ozone
198335327651206003784192Ozone
19823582596219153039105269Ozone
198114093271064043133257Ozone

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.

All monitored counties in Texas

Source: U.S. EPA AirData, “Annual AQI by County” files for 1981–1987 (EPA download page). EPA file dates: 2026-06-26. Imported into EnviroNearby November 5, 2026. How we use this data · Report a problem