Williams, North Dakota Air Quality
Williams County, North Dakota (ND)
→ Stableover 6 years
How Williams, North Dakota Air Quality Compares
Williams, North Dakota's median AQI of 34is 17% better than the national average of 41. The area rarely experiences unhealthy air quality days. The primary pollutant of concern is Ground-Level Ozone.
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 |
|---|---|---|---|---|---|---|---|
| 2019 | 34 | 51 | 77 | 324 | 38 | 0 | Ozone |
| 2018 | 38 | 59 | 100 | 291 | 69 | 0 | Ozone |
| 2017 | 37 | 54 | 131 | 302 | 58 | 2 | Ozone |
| 2016 | 32 | 45 | 94 | 349 | 15 | 0 | Ozone |
| 2015 | 36 | 56 | 182 | 307 | 49 | 8 | Ozone |
| 2014 | 37 | 56 | 114 | 295 | 69 | 1 | Ozone |
What This Means for Williams County Residents
Williams, North Dakota has received an Air Quality Grade of B (70/100) based on a decade of monitoring data from the EPA's air quality monitoring program. The current median AQI of 34 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 North Dakota
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Frequently Asked Questions
Williams, North Dakota has a current median AQI of 34, which falls in the "Good" range. The area has received an Air Quality Grade of B (70/100) based on 10 years of EPA monitoring data.
Air quality in Williams, North Dakota is stable over the past decade. The median AQI has changed by -3 points from 2014 to 2019.
Williams, North Dakota 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 Williams, North Dakota is Ground-Level Ozone. This is the dominant contributor to elevated AQI readings in the Williams County area.
Williams, North Dakota 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 34 (Good), outdoor exercise in Williams, North Dakota is generally safe year-round. Williams, North Dakota averages 0 days per year when athletes should move workouts indoors.
this entity is one of the data points covered by this site’s U.S. air quality and pollution monitoring dataset. The detail above comes directly from the EPA Air Quality System (AQS); the context that follows situates the headline numbers against the broader distribution across U.S. counties and states.
The methodology behind every numeric value on this page is publicly documented on the the EPA Air Quality System (AQS) portal and described in detail on this site’s methodology page. Refresh cadence varies by underlying series; the page surfaces the as-of date for each number so readers can trace any figure back to the source release.
Practical use of this page is in combination with the comparison and ranking pages elsewhere on the site, which surface the same data for this entity’s peers within U.S. counties and states. A single-entity reading without peer context can be misleading when an entity is an outlier on one axis but typical on another.