Whatcom, Washington Air Quality
Whatcom County, Washington (WA)
↓ Improvingover 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). 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 | 49 | 94 | 327 | 33 | 0 | PM2.5 |
| 2022 | 32 | 56 | 243 | 294 | 40 | 9 | Ozone |
| 2021 | 28 | 42 | 129 | 323 | 7 | 2 | PM2.5 |
| 2020 | 24 | 44 | 237 | 341 | 16 | 9 | PM2.5 |
| 2019 | 29 | 47 | 66 | 334 | 29 | 0 | PM2.5 |
| 2018 | 29 | 52 | 193 | 319 | 33 | 9 | PM2.5 |
| 2017 | 31 | 54 | 187 | 300 | 41 | 7 | PM2.5 |
| 2016 | 28 | 46 | 64 | 322 | 27 | 0 | PM2.5 |
| 2015 | 34 | 53 | 91 | 279 | 52 | 0 | PM2.5 |
| 2014 | 38 | 57 | 81 | 236 | 103 | 0 | PM2.5 |
What This Means for Whatcom County Residents
Whatcom, Washington has received an Air Quality Grade of B (73/100) based on a decade of EPA monitoring data. The current median AQI of 31 falls in the "Good" range.
Encouragingly, air quality here has been improving, with the median AQI dropping by 7 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 4 unhealthy air quality days per year — days when sensitive groups (children, elderly, those with respiratory conditions) should limit outdoor activity.