Knox, Indiana Air Quality
Knox County, Indiana (IN)
↑ Worseningover 10 years
How Knox, Indiana Air Quality Compares
Knox, Indiana's median AQI of 39is 5% better than the national average of 41. Air quality has worsened by 5 AQI points over the past decade. The area averages 2 unhealthy air days per year. The primary pollutant of concern is Ground-Level Ozone.
10-Year AQI Trend
The solid line shows the median AQI each year. The dashed line shows the 90th percentile (worst 10% of days). Air quality in this area has been declining over the past decade.
Air Quality Day Breakdown
Number of days per year in each EPA AQI category. Green = Good (AQI 0-50), Yellow = Moderate (51-100), Orange = Unhealthy for Sensitive Groups (101-150), Red = Unhealthy or worse (151+).
Year-by-Year Data
| Year | Median AQI | 90th Pct | Max AQI | Good Days | Moderate | Unhealthy+ | Pollutant |
|---|---|---|---|---|---|---|---|
| 2023 | 39 | 58 | 126 | 313 | 43 | 8 | Ozone |
| 2022 | 36 | 48 | 87 | 321 | 23 | 0 | Ozone |
| 2021 | 36 | 51 | 108 | 320 | 38 | 2 | Ozone |
| 2020 | 33 | 48 | 105 | 328 | 22 | 1 | Ozone |
| 2019 | 36 | 50 | 87 | 328 | 31 | 0 | Ozone |
| 2018 | 35 | 54 | 122 | 311 | 42 | 4 | Ozone |
| 2017 | 36 | 50 | 100 | 323 | 32 | 0 | Ozone |
| 2016 | 35 | 61 | 119 | 313 | 42 | 4 | Ozone |
| 2015 | 34 | 51 | 93 | 314 | 35 | 0 | Ozone |
| 2014 | 34 | 51 | 90 | 313 | 35 | 0 | Ozone |
What This Means for Knox County Residents
Knox, Indiana has received an Air Quality Grade of C (64/100) based on a decade of monitoring data from the EPA's air quality monitoring program. The current median AQI of 39 falls in the "Good" range.
Concerning trends show air quality has been declining, with the median AQI rising by 5 points over the monitoring period. This could be driven by increased development, wildfire smoke, or industrial activity.
The primary pollutant affecting this area is Ground-Level Ozone. Over the past 5 years, this area has averaged 2 unhealthy air quality days per year, days when sensitive groups (children, elderly, those with respiratory conditions) should limit outdoor activity. The American Lung Association's State of the Air report provides additional context on long-term health risks from air pollution exposure.
Related Cities in Indiana
Frequently Asked Questions
Knox, Indiana has a current median AQI of 39, which falls in the "Good" range. The area has received an Air Quality Grade of C (64/100) based on 10 years of EPA monitoring data.
Air quality in Knox, Indiana is worsening over the past decade. The median AQI has changed by +5 points from 2014 to 2023.
Knox, Indiana averages 2 unhealthy air quality days per year over the past 5 years. On these days, sensitive groups including children, the elderly, and those with respiratory conditions should limit outdoor activity.
The primary pollutant affecting Knox, Indiana is Ground-Level Ozone. This is the dominant contributor to elevated AQI readings in the Knox County area.
Knox, Indiana averages 2 unhealthy air days per year. This is relatively low, making it a reasonable choice for asthma sufferers. The primary pollutant is Ground-Level Ozone, which is a known asthma trigger.
With a median AQI of 39 (Good), outdoor exercise in Knox, Indiana is generally safe year-round. Knox, Indiana averages 2 days per year when athletes should move workouts indoors.
this entity is one of the data points covered by this site’s U.S. air quality and pollution monitoring dataset. The detail above comes directly from the EPA Air Quality System (AQS); the context that follows situates the headline numbers against the broader distribution across U.S. counties and states.
Every number on this page links back to the EPA Air Quality System (AQS); the methodology page describes the inputs, refresh cadence, and known limitations of the underlying data product.
Practical use of this page is in combination with the comparison and ranking pages elsewhere on the site, which surface the same data for this entity’s peers within U.S. counties and states. A single-entity reading without peer context can be misleading when an entity is an outlier on one axis but typical on another.