Delaware, Ohio Air Quality
Delaware County, Ohio (OH)
→ Stableover 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).
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 | 41 | 54 | 108 | 211 | 33 | 1 | Ozone |
| 2022 | 37 | 47 | 100 | 230 | 14 | 0 | Ozone |
| 2021 | 38 | 49 | 77 | 222 | 18 | 0 | Ozone |
| 2020 | 38 | 50 | 101 | 222 | 21 | 1 | Ozone |
| 2019 | 41 | 51 | 84 | 214 | 27 | 0 | Ozone |
| 2018 | 39 | 54 | 100 | 212 | 32 | 0 | Ozone |
| 2017 | 38 | 49 | 90 | 228 | 17 | 0 | Ozone |
| 2016 | 41 | 67 | 112 | 179 | 32 | 1 | Ozone |
| 2015 | 39 | 54 | 108 | 187 | 26 | 1 | Ozone |
| 2014 | 41 | 54 | 105 | 188 | 24 | 2 | Ozone |
What This Means for Delaware County Residents
Delaware, Ohio has received an Air Quality Grade of B (68/100) based on a decade of monitoring data from the EPA's air quality monitoring program. The current median AQI of 41 falls in the "Good" range.
The primary pollutant affecting this area is Ground-Level Ozone. Over the past 5 years, this area has averaged 0 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 Ohio
Frequently Asked Questions
Delaware, Ohio has a current median AQI of 41, which falls in the "Good" range. The area has received an Air Quality Grade of B (68/100) based on 10 years of EPA monitoring data.
Air quality in Delaware, Ohio is stable over the past decade. The median AQI has changed by 0 points from 2014 to 2023.
Delaware, Ohio averages 0 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 Delaware, Ohio is Ground-Level Ozone. This is the dominant contributor to elevated AQI readings in the Delaware County area.
Delaware, Ohio averages 0 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 41 (Good), outdoor exercise in Delaware, Ohio is generally safe year-round. Delaware, Ohio averages 0 days per year when athletes should move workouts indoors.