Marathon, Wisconsin Air Quality
Marathon County, Wisconsin (WI)
→ 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 | 84 | 166 | 168 | 39 | 9 | Ozone |
| 2022 | 35 | 46 | 64 | 197 | 8 | 0 | Ozone |
| 2021 | 36 | 49 | 87 | 191 | 9 | 0 | Ozone |
| 2020 | 31 | 45 | 74 | 193 | 6 | 0 | Ozone |
| 2019 | 34 | 47 | 84 | 196 | 9 | 0 | Ozone |
| 2018 | 39 | 54 | 97 | 205 | 27 | 0 | Ozone |
| 2017 | 36 | 47 | 90 | 223 | 14 | 0 | Ozone |
| 2016 | 35 | 49 | 100 | 176 | 16 | 0 | Ozone |
| 2015 | 36 | 48 | 90 | 192 | 12 | 0 | Ozone |
| 2014 | 38 | 49 | 101 | 179 | 14 | 1 | Ozone |
What This Means for Marathon County Residents
Marathon, Wisconsin has received an Air Quality Grade of B (67/100) 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 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 Wisconsin
Frequently Asked Questions
Marathon, Wisconsin has a current median AQI of 41, which falls in the "Good" range. The area has received an Air Quality Grade of B (67/100) based on 10 years of EPA monitoring data.
Air quality in Marathon, Wisconsin is stable over the past decade. The median AQI has changed by +3 points from 2014 to 2023.
Marathon, Wisconsin 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 Marathon, Wisconsin is Ground-Level Ozone. This is the dominant contributor to elevated AQI readings in the Marathon County area.
Marathon, Wisconsin averages 2 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 Marathon, Wisconsin is generally safe year-round. Marathon, Wisconsin averages 2 days per year when athletes should move workouts indoors.