Jefferson, Oregon Air Quality
Jefferson County, Oregon (OR)
↓ Improvingover 9 years
How Jefferson, Oregon Air Quality Compares
Jefferson, Oregon's median AQI of 31is 24% better than the national average of 41. Air quality has improved by 13 AQI points over the past decade. The area averages 5 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 | 31 | 63 | 238 | 266 | 93 | 6 | PM2.5 |
| 2022 | 26 | 63 | 108 | 272 | 92 | 1 | PM2.5 |
| 2021 | 28 | 61 | 173 | 282 | 77 | 6 | PM2.5 |
| 2020 | 28 | 64 | 1135 | 258 | 92 | 11 | PM2.5 |
| 2019 | 29 | 66 | 122 | 261 | 102 | 2 | PM2.5 |
| 2018 | 49 | 72 | 156 | 96 | 82 | 6 | PM2.5 |
| 2017 | 37 | 99 | 242 | 54 | 29 | 9 | PM2.5 |
| 2015 | 42 | 81 | 160 | 60 | 28 | 4 | PM2.5 |
| 2014 | 44 | 67 | 184 | 52 | 28 | 2 | PM2.5 |
What This Means for Jefferson County Residents
Jefferson, Oregon has received an Air Quality Grade of A (83/100) based on a decade of monitoring data from the EPA's air quality monitoring program. The current median AQI of 31 falls in the "Good" range.
Encouragingly, air quality here has been improving, with the median AQI dropping by 13 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 5 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 Oregon
Frequently Asked Questions
Jefferson, Oregon has a current median AQI of 31, which falls in the "Good" range. The area has received an Air Quality Grade of A (83/100) based on 10 years of EPA monitoring data.
Air quality in Jefferson, Oregon is improving over the past decade. The median AQI has changed by -13 points from 2014 to 2023.
Jefferson, Oregon averages 5 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 Jefferson, Oregon is Fine Particulate Matter (PM2.5). This is the dominant contributor to elevated AQI readings in the Jefferson County area.
Jefferson, Oregon averages 5 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 31 (Good), outdoor exercise in Jefferson, Oregon is generally safe year-round. Jefferson, Oregon averages 5 days per year when athletes should move workouts indoors.
The this entity record above pulls directly from the EPA Air Quality System (AQS). What follows is the per-entity context — how this entity sits in the broader U.S. air quality and pollution monitoring distribution and which underlying factors drive the headline numbers.
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.
For readers using this page as a decision input, the related-entity pages elsewhere on the site provide the comparison set. The most useful comparison for this entity is typically a peer within U.S. counties and states with similar size, similar exposure, or similar geography — not the national-level summary alone.