Allegheny, Pennsylvania Air Quality
Allegheny County, Pennsylvania (PA)
→ Stableover 10 years
How Allegheny, Pennsylvania Air Quality Compares
Allegheny, Pennsylvania's median AQI of 56is 37% worse than the national average of 41. Residents experience an average of 11 unhealthy air days per year, above the national threshold for concern. The primary pollutant of concern is Fine Particulate Matter (PM2.5).
Allegheny, Pennsylvania Air Quality: The Full Picture
Allegheny, Pennsylvania (Allegheny County) holds an AirHistory Air Quality Grade of C (fair, scoring 54 out of 100), built from 10 years of EPA Air Quality System monitoring. Its median AQI fell 2 points between 2014 (58) and 2023 (56), and the five-year median now sits at 56 — inside the "Moderate" band on the EPA scale.
The pollutant driving most of the area's AQI readings is Fine Particulate Matter (PM2.5). In 2023, it set the daily AQI on 294 of 365 monitored days (81% of the year), making it the controlling pollutant for the C grade. The single worst reading logged that year hit an AQI of 237 (Very Unhealthy), while the 90th-percentile day — the level the dirtiest 10% of days reach — came in at 84.
In 2023, Allegheny County recorded 121 "Good" air days (33% of the 365 days with valid AQI data), 227 "Moderate" days, and 17 days at "Unhealthy for Sensitive Groups" or above. Over the most recent five years on record, monitors logged 56 days that crossed into "Unhealthy for Sensitive Groups" or worse — about 11 per year.
The decade-long trend is essentially flat, with year-to-year median AQI shifting by less than 0.23 points per year on average. The cleanest year in the record was 2020 (median AQI 54), and the most polluted was 2019 (median AQI 59). Because the data come straight from federally certified EPA monitors, these figures track the Pennsylvania county the monitors physically sit in rather than a city boundary.
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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 | 56 | 84 | 237 | 121 | 227 | 17 | PM2.5 |
| 2022 | 56 | 84 | 151 | 129 | 225 | 11 | PM2.5 |
| 2021 | 57 | 84 | 154 | 118 | 240 | 7 | PM2.5 |
| 2020 | 54 | 77 | 128 | 138 | 218 | 10 | PM2.5 |
| 2019 | 59 | 80 | 165 | 67 | 287 | 11 | PM2.5 |
| 2018 | 58 | 84 | 154 | 92 | 260 | 13 | PM2.5 |
| 2017 | 58 | 87 | 168 | 111 | 235 | 19 | PM2.5 |
| 2016 | 56 | 84 | 152 | 103 | 243 | 20 | PM2.5 |
| 2015 | 58 | 90 | 157 | 105 | 241 | 19 | PM2.5 |
| 2014 | 58 | 80 | 157 | 99 | 256 | 10 | PM2.5 |
What This Means for Allegheny County Residents
Allegheny, Pennsylvania has received an Air Quality Grade of C (54/100) based on a decade of monitoring data from the EPA's air quality monitoring program. The current median AQI of 56 falls in the "Moderate" range.
The primary pollutant affecting this area is Fine Particulate Matter (PM2.5). Over the past 5 years, this area has averaged 11 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.
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Frequently Asked Questions
Allegheny, Pennsylvania has a current median AQI of 56, which falls in the "Moderate" range. The area has received an Air Quality Grade of C (54/100) based on 10 years of EPA monitoring data.
Air quality in Allegheny, Pennsylvania is stable over the past decade. The median AQI has changed by -2 points from 2014 to 2023.
Allegheny, Pennsylvania averages 11 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 Allegheny, Pennsylvania is Fine Particulate Matter (PM2.5). This is the dominant contributor to elevated AQI readings in the Allegheny County area.
Allegheny, Pennsylvania averages 11 unhealthy air days per year. Asthma patients should monitor daily AQI readings and limit outdoor activity when AQI exceeds 100. The primary pollutant is Fine Particulate Matter (PM2.5), which is a known asthma trigger.
With a median AQI of 56 (Moderate), outdoor exercise in Allegheny, Pennsylvania is safe most days, though sensitive individuals should check daily AQI before intense workouts. Allegheny, Pennsylvania averages 11 days per year when athletes should move workouts indoors.