Hamilton, Indiana Air Quality
Hamilton County, Indiana (IN)
↓ Improvingover 10 years
How Hamilton, Indiana Air Quality Compares
Hamilton, Indiana's median AQI of 46is 12% worse than the national average of 41. The area averages 2 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). 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 | 46 | 69 | 190 | 220 | 134 | 10 | PM2.5 |
| 2022 | 43 | 63 | 100 | 241 | 124 | 0 | PM2.5 |
| 2021 | 44 | 66 | 100 | 232 | 133 | 0 | PM2.5 |
| 2020 | 44 | 59 | 97 | 247 | 119 | 0 | PM2.5 |
| 2019 | 47 | 64 | 119 | 214 | 149 | 2 | PM2.5 |
| 2018 | 45 | 63 | 129 | 229 | 130 | 6 | PM2.5 |
| 2017 | 46 | 60 | 105 | 229 | 134 | 2 | PM2.5 |
| 2016 | 49 | 65 | 115 | 189 | 167 | 3 | PM2.5 |
| 2015 | 44 | 64 | 93 | 213 | 147 | 0 | PM2.5 |
| 2014 | 48 | 66 | 129 | 191 | 165 | 2 | PM2.5 |
What This Means for Hamilton County Residents
Hamilton, 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 46 falls in the "Good" range.
Encouragingly, air quality here has been improving, with the median AQI dropping by 2 points over the monitoring period. This trend suggests continued investment in emission controls and cleaner energy.
The primary pollutant affecting this area is Fine Particulate Matter (PM2.5). 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
Hamilton, Indiana has a current median AQI of 46, 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 Hamilton, Indiana is improving over the past decade. The median AQI has changed by -2 points from 2014 to 2023.
Hamilton, 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 Hamilton, Indiana is Fine Particulate Matter (PM2.5). This is the dominant contributor to elevated AQI readings in the Hamilton County area.
Hamilton, Indiana averages 2 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, Indiana is generally safe year-round. Hamilton, Indiana averages 2 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.
The methodology behind every numeric value on this page is publicly documented on the the EPA Air Quality System (AQS) portal and described in detail on this site’s methodology page. Refresh cadence varies by underlying series; the page surfaces the as-of date for each number so readers can trace any figure back to the source release.
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.