EnviroNearby

Kankakee County, Illinois air quality history

Daily Air Quality Index summaries from EPA monitors in Kankakee, Illinois, 1981–1986.

89%
Good days in 1985
27
Median daily AQI, 1985
5
Days above 100 in 1985
349
Days with an AQI in 1985 (of 365)

In 1985, EPA reported a daily Air Quality Index (AQI) for Kankakee, Illinois on 349 days. 309 of those days (89%) were in the Good range, and the median daily AQI was 27. That median is lower than the typical monitored county in Illinois (median 35 across 20 counties), and lower than the typical monitored U.S. county (40.5). The main pollutant was ozone on 349 days.

The most recent year with data for this county is 1986; EPA's files for 1987–2025 contain no row for it, which usually means its monitors stopped reporting.

Years with fewer than 120 monitored days (1986) 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 139 of 147 days1981: Moderate 6 of 147 days1981: Unhealthy for Sensitive Groups 2 of 147 days19811982: Good 281 of 311 days1982: Moderate 26 of 311 days1982: Unhealthy for Sensitive Groups 3 of 311 days1982: Very Unhealthy 1 of 311 days19821983: Good 267 of 310 days1983: Moderate 34 of 310 days1983: Unhealthy for Sensitive Groups 8 of 310 days1983: Very Unhealthy 1 of 310 days19831984: Good 266 of 304 days1984: Moderate 37 of 304 days1984: Unhealthy for Sensitive Groups 1 of 304 days19841985: Good 309 of 349 days1985: Moderate 35 of 349 days1985: Unhealthy for Sensitive Groups 5 of 349 days19851986: Good 50 of 50 days1986
  • 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 year0501001981: 90th percentile AQI 491982: 90th percentile AQI 491983: 90th percentile AQI 611984: 90th percentile AQI 581985: 90th percentile AQI 581986: 90th percentile AQI 271981: Median AQI 281982: Median AQI 261983: Median AQI 311984: Median AQI 311985: Median AQI 271986: Median AQI 19198119821983198419851986
  • Median daily AQI
  • 90th-percentile daily AQI

Main pollutant by day, 1985

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
Ozone349100%

Year-by-year data

Annual AQI summary by year
YearDays with AQIGoodModerateUnhealthy for Sensitive GroupsUnhealthyVery UnhealthyHazardousMedian AQI90th pct.Max AQIMain pollutant
1986505000000192732Ozone
19853493093550002758126Ozone
19843042663710003158105Ozone
19833102673480103161203Ozone
19823112812630102649208Ozone
1981147139620002849129Ozone

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 Illinois

Source: U.S. EPA AirData, “Annual AQI by County” files for 1981–1986 (EPA download page). EPA file dates: 2026-06-26. Imported into EnviroNearby November 5, 2026. How we use this data · Report a problem