Clark, Illinois Air Quality
Clark County, Illinois (IL)
↓ Improvingover 10 years
10-Year AQI Trend
The solid line shows the median AQI each year. The dashed line shows the 90th percentile (worst 10% of days). This area has seen measurable air quality improvement over the 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 | 36 | 51 | 136 | 320 | 33 | 5 | Ozone |
| 2022 | 34 | 45 | 101 | 296 | 15 | 1 | Ozone |
| 2021 | 34 | 46 | 84 | 344 | 19 | 0 | Ozone |
| 2020 | 31 | 45 | 97 | 347 | 16 | 0 | Ozone |
| 2019 | 34 | 47 | 74 | 314 | 13 | 0 | Ozone |
| 2018 | 32 | 48 | 101 | 337 | 21 | 1 | Ozone |
| 2017 | 39 | 51 | 101 | 211 | 29 | 1 | Ozone |
| 2016 | 38 | 54 | 101 | 175 | 27 | 1 | Ozone |
| 2015 | 39 | 61 | 87 | 182 | 28 | 0 | Ozone |
| 2014 | 39 | 51 | 90 | 185 | 26 | 0 | Ozone |
What This Means for Clark County Residents
Clark, Illinois has received an Air Quality Grade of B (73/100) based on a decade of EPA monitoring data. The current median AQI of 36 falls in the "Good" range.
Encouragingly, air quality here has been improving, with the median AQI dropping by 3 points over the monitoring period. This trend suggests continued investment in emission controls and cleaner energy.
The primary pollutant affecting this area is Ground-Level Ozone. Over the past 5 years, this area has averaged 1 unhealthy air quality days per year — days when sensitive groups (children, elderly, those with respiratory conditions) should limit outdoor activity.