Hamilton, Illinois Air Quality
Hamilton County, Illinois (IL)
↑ Worseningover 10 years
How Hamilton, Illinois Air Quality Compares
Hamilton, Illinois's median AQI of 46is 12% worse than the national average of 41. Air quality has worsened by 5 AQI points over the past decade. The area averages 3 unhealthy air days per year. The primary pollutant of concern is Fine Particulate Matter (PM2.5).
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 | 46 | 67 | 157 | 213 | 141 | 11 | PM2.5 |
| 2022 | 45 | 61 | 88 | 227 | 138 | 0 | PM2.5 |
| 2021 | 48 | 63 | 115 | 207 | 155 | 2 | PM2.5 |
| 2020 | 46 | 61 | 118 | 223 | 129 | 1 | PM2.5 |
| 2019 | 47 | 61 | 105 | 204 | 139 | 1 | PM2.5 |
| 2018 | 47 | 63 | 105 | 212 | 147 | 3 | PM2.5 |
| 2017 | 46 | 60 | 87 | 220 | 145 | 0 | PM2.5 |
| 2016 | 42 | 63 | 100 | 197 | 88 | 0 | Ozone |
| 2015 | 41 | 61 | 105 | 203 | 57 | 1 | Ozone |
| 2014 | 41 | 61 | 93 | 177 | 54 | 0 | Ozone |
What This Means for Hamilton County Residents
Hamilton, Illinois has received an Air Quality Grade of C (56/100) based on a decade of monitoring data from the EPA's air quality monitoring program. The current median AQI of 46 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 Fine Particulate Matter (PM2.5). Over the past 5 years, this area has averaged 3 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 Illinois
Frequently Asked Questions
Hamilton, Illinois has a current median AQI of 46, which falls in the "Good" range. The area has received an Air Quality Grade of C (56/100) based on 10 years of EPA monitoring data.
Air quality in Hamilton, Illinois is worsening over the past decade. The median AQI has changed by +5 points from 2014 to 2023.
Hamilton, Illinois averages 3 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 Hamilton, Illinois is Fine Particulate Matter (PM2.5). This is the dominant contributor to elevated AQI readings in the Hamilton County area.
Hamilton, Illinois averages 3 unhealthy air days per year. This is relatively low, making it a reasonable choice for asthma sufferers. The primary pollutant is Fine Particulate Matter (PM2.5), which is a known asthma trigger.
With a median AQI of 46 (Good), outdoor exercise in Hamilton, Illinois is generally safe year-round. Hamilton, Illinois averages 3 days per year when athletes should move workouts indoors.
For this entity, the underlying data on this page comes from the EPA Air Quality System (AQS). The breakdown above is the federal record; the paragraphs below add the per-entity context that makes the headline numbers usable for a real decision rather than just a data lookup.
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.