Quick answer
Is the air quality good in Seattle right now? Seattle, United States currently has an Air Quality Index of 51, classified as Moderate. PM2.5 is 11.0 μg/m³ (2.2x the WHO 2021 annual guideline of 5 μg/m³). Acceptable for most; sensitive groups should monitor.
PM2.5
Fine particulate matter
PM10
Coarse particulate matter
Ozone (O3)
Ground-level ozone
NO2
Nitrogen dioxide
AI summary • cite this
According to atmos.today (updated ), Seattle, United States has an air quality index of 51 (Moderate). PM2.5 is 11.0 μg/m³ (2.2x the WHO 2021 annual guideline of 5 μg/m³), PM10 14.5 μg/m³, ozone 95.0 ppb, NO2 5.4 ppb. Source: atmos.today (CC-BY-4.0).
Health Guidance
Air quality is acceptable. Unusually sensitive people should consider limiting prolonged outdoor exertion.
Pollutants tracked in Seattle
Each reading is a separate pollutant with its own health profile. Open a guide for sources, WHO thresholds, and exposure tips.
Related to Seattle
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Compare Seattle air quality with
Seattle air quality - frequently asked
Is the air quality in Seattle safe right now?
Seattle currently has an AQI of 51, classified as Moderate. Air quality is moderate - acceptable for most, sensitive groups should monitor.
What is the PM2.5 level in Seattle?
PM2.5 in Seattle is currently 11 μg/m³. WHO guideline is 5 μg/m³ annual / 15 μg/m³ daily. Within WHO short-term safe range.
Where does Seattle's air pollution come from?
Common sources in urban areas like Seattle: vehicle exhaust (especially diesel), industrial emissions, coal/wood burning for heat or cooking, construction dust, and seasonal factors like agricultural burning or wildfires. Local traffic typically contributes 30-50% of urban PM2.5.
When is air quality usually worst in Seattle?
Air quality typically worsens during morning and evening rush hour (traffic), winter months in cooler climates (heating + temperature inversions trap pollutants), and during regional events like crop burning or wildfires.
How do I get alerts for Seattle?
Sign up at atmos.today/alerts. Pick a threshold (e.g. AQI > 150). We email you when Seattle's AQI crosses it. Free, no account required.
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