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AirHistory

What Is the Air Quality in Clallam, Washington?

Clallam, Washington has an Air Quality Grade of B (good) with a 5-year median AQI of 37. The dominant pollutant is Fine Particulate Matter (PM2.5), and air quality has been improving over the past decade.

Clallam, Washington Air Quality Snapshot

Air Quality GradeB69/100
5-Year Median AQI37 (Good)
Most Recent Median AQI (2023)37 (Good)
Dominant PollutantFine Particulate Matter (PM2.5)
10-Year TrendImproving (-0.48 AQI/yr)
Unhealthy Days (last 5 yr)10
National Rank (cleanest = #1)#339 of 1,020 (33th cleanest percentile)
Washington Rank#21 of 30

What Does the B Grade Mean?

Clallam, Washington earns a B — air quality is reliably in the safe range for most residents most of the time, with a 5-year median AQI of 37. Sensitive groups will see occasional caution days, but the typical resident will not need to change behavior based on air quality.

Clallam, Washington's 5-year median AQI of 37 is 4 points below the national average of 41 — meaningfully cleaner than the typical U.S. metro tracked here. Within Washington, Clallam, Washington runs more polluted than the state average of 31 — local sources or geography are concentrating pollution above the state's typical reading.

For context within Washington: Garfield, Washington currently holds the state's cleanest grade (A, AQI 20), while Asotin, Washington sits at the bottom (D, AQI 43).

What's in Clallam, Washington's Air?

The dominant pollutant in Clallam, Washington is Fine Particulate Matter (PM2.5). Fine particulate matter — particles less than 2.5 micrometers across — comes mostly from combustion: vehicle exhaust, wildfire smoke, residential wood burning, and industrial emissions. Because these particles are small enough to enter the bloodstream, PM2.5 is the pollutant most strongly linked to cardiovascular disease, respiratory illness, and premature death.

Days by Dominant Pollutant (2023)

PollutantDays as DominantShare of Year
Ground-Level Ozone18651%
Fine Particulate Matter (PM2.5)17949%

Is the Air Getting Better or Worse?

Air quality in Clallam, Washington has been improving over the past decade, with median AQI dropping by roughly 0.5 points per year. That is consistent with the broader national pattern — most U.S. metros have seen steady reductions in particulate and ozone pollution since the 2010s as cleaner vehicles and power plants come online.

In 2014, Clallam, Washington posted a median AQI of 40. By 2023 that figure was 37 — a drop of 3 AQI points cleaner across 10 years of EPA records.

Year-by-Year AQI in Clallam, Washington

YearMedian AQIGood DaysUnhealthy DaysDominant Pollutant
2014402791PM2.5
2015412630PM2.5
2016402790PM2.5
2017412468PM2.5
2018422438PM2.5
2019382850PM2.5
2020373047PM2.5
2021372980Ozone
2022382722Ozone
2023373071Ozone

Health Context for Clallam, Washington

Across the past five years, this area has logged just 10 days where AQI rose into the "Unhealthy for Sensitive Groups" range or worse — about 2 days per year, or roughly one every other month. That is a low count by national standards.

For most healthy adults, current air quality in this area does not require any change in behavior. People with severe asthma, COPD, or recent cardiac events should still keep an eye on daily AQI alerts, especially during wildfire season. Because PM2.5 penetrates deep into the lungs and bloodstream, an N95 or KN95 mask provides meaningful protection on smoky or high-particulate days — surgical masks do not.

How This Grade Is Calculated

The AirHistory Air Quality Grade combines four signals: the 5-year median AQI (40% of the score), the 10-year trend direction (30%), the count of unhealthy days per year (20%), and the dominant pollutant type (10%). All four come directly from the EPA Air Quality System (AQS), which aggregates readings from federally certified monitors. Read the full methodology.

Clallam, Washington has an Air Quality Grade of B (good) with a 5-year median AQI of 37. The dominant pollutant is Fine Particulate Matter (PM2.5), and air quality has been improving over the past decade.

This answer pulls from the EPA Air Quality System (AQS), the authoritative federal source for U.S. air quality and pollution monitoring. The headline number above is the direct answer; what follows is the additional context most readers need to use the answer for a real decision rather than just a fact lookup.

A practical caveat: the headline answer above reflects the most recent the EPA Air Quality System (AQS) vintage; underlying data is often revised for months after first publication, and the right reference for any specific decision is whichever vintage is current at the time of the decision. The as-of date is stamped on every page.

Source: EPA Outdoor Air Quality Data, 2026.