Quick answer
Is the air quality good in San Diego right now? San Diego, United States currently has an Air Quality Index of 59, classified as Moderate. PM2.5 is 21.5 μg/m³ (4.3x 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 Diego, United States has an air quality index of 59 (Moderate). PM2.5 is 21.5 μg/m³ (4.3x the WHO 2021 annual guideline of 5 μg/m³), PM10 26.4 μg/m³, ozone 21.0 ppb, NO2 56.2 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 Diego
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 Diego air quality - frequently asked
Is the air quality in San Diego safe right now?
San Diego currently has an AQI of 59, classified as Moderate. Air quality is moderate - acceptable for most, sensitive groups should monitor.
What is the PM2.5 level in San Diego?
PM2.5 in San Diego is currently 21.5 μg/m³. WHO guideline is 5 μg/m³ annual / 15 μg/m³ daily. Within WHO short-term safe range.
Where does San Diego's air pollution come from?
Common sources in urban areas like San Diego: 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 Diego?
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 Diego?
Sign up at atmos.today/alerts. Pick a threshold (e.g. AQI > 150). We email you when San Diego's AQI crosses it. Free, no account required.
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