Bristol, Massachusetts Air Quality
Bristol County, Massachusetts (MA)
→ 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 | 42 | 61 | 137 | 269 | 87 | 9 | Ozone |
| 2022 | 38 | 54 | 115 | 301 | 63 | 1 | Ozone |
| 2021 | 39 | 56 | 147 | 279 | 84 | 2 | Ozone |
| 2020 | 42 | 58 | 119 | 250 | 113 | 3 | Ozone |
| 2019 | 43 | 56 | 97 | 279 | 85 | 0 | Ozone |
| 2018 | 44 | 59 | 133 | 258 | 97 | 10 | Ozone |
| 2017 | 42 | 61 | 151 | 260 | 99 | 6 | Ozone |
| 2016 | 37 | 55 | 133 | 307 | 55 | 4 | Ozone |
| 2015 | 39 | 61 | 122 | 260 | 100 | 5 | Ozone |
| 2014 | 43 | 60 | 84 | 243 | 122 | 0 | PM2.5 |
What This Means for Bristol County Residents
Bristol, Massachusetts has received an Air Quality Grade of B (65/100) based on a decade of monitoring data from the EPA's air quality monitoring program. The current median AQI of 42 falls in the "Good" range.
The primary pollutant affecting this area is Ground-Level Ozone. 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 Massachusetts
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Frequently Asked Questions
Bristol, Massachusetts has a current median AQI of 42, which falls in the "Good" range. The area has received an Air Quality Grade of B (65/100) based on 10 years of EPA monitoring data.
Air quality in Bristol, Massachusetts is stable over the past decade. The median AQI has changed by -1 points from 2014 to 2023.
Bristol, Massachusetts 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 Bristol, Massachusetts is Ground-Level Ozone. This is the dominant contributor to elevated AQI readings in the Bristol County area.
Bristol, Massachusetts averages 3 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 42 (Good), outdoor exercise in Bristol, Massachusetts is generally safe year-round. Bristol, Massachusetts averages 3 days per year when athletes should move workouts indoors.