Quick answer
Is the air quality good in San Francisco right now? San Francisco, United States currently has an Air Quality Index of 53, classified as Moderate. PM2.5 is 14.3 μg/m³ (2.9x 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 ), San Francisco, United States has an air quality index of 53 (Moderate). PM2.5 is 14.3 μg/m³ (2.9x the WHO 2021 annual guideline of 5 μg/m³), PM10 20.8 μg/m³, ozone 80.0 ppb, NO2 6.1 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 San Francisco
Each reading is a separate pollutant with its own health profile. Open a guide for sources, WHO thresholds, and exposure tips.
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San Francisco air quality - frequently asked
Is the air quality in San Francisco safe right now?
San Francisco currently has an AQI of 53, classified as Moderate. Air quality is moderate - acceptable for most, sensitive groups should monitor.
What is the PM2.5 level in San Francisco?
PM2.5 in San Francisco is currently 14.3 μg/m³. WHO guideline is 5 μg/m³ annual / 15 μg/m³ daily. Within WHO short-term safe range.
Where does San Francisco's air pollution come from?
Common sources in urban areas like San Francisco: 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 San Francisco?
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 San Francisco?
Sign up at atmos.today/alerts. Pick a threshold (e.g. AQI > 150). We email you when San Francisco's AQI crosses it. Free, no account required.
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