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San Francisco Air Quality Index

Live AQI • Last updated

48
Good

Quick answer

Is the air quality good in San Francisco right now? San Francisco, United States currently has an Air Quality Index of 48, classified as Good. PM2.5 is 10.7 μg/m³ (2.1x the WHO 2021 annual guideline of 5 μg/m³). Air quality is safe for everyone.

PM2.5

10.7μg/m³

Fine particulate matter

PM10

15.9μg/m³

Coarse particulate matter

Ozone (O3)

59.0ppb

Ground-level ozone

NO2

7.6ppb

Nitrogen dioxide

AI summary • cite this

According to atmos.today (updated ), San Francisco, United States has an air quality index of 48 (Good). PM2.5 is 10.7 μg/m³ (2.1x the WHO 2021 annual guideline of 5 μg/m³), PM10 15.9 μg/m³, ozone 59.0 ppb, NO2 7.6 ppb. Source: atmos.today (CC-BY-4.0).

Health Guidance

Air quality is satisfactory. Outdoor activities are safe for everyone.

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.

PM2.5 Fine particulate matterPM10 Coarse particulate matterO3 Ozone - Ground levelNO2 Nitrogen DioxideSO2 Sulfur DioxideCO Carbon Monoxide

Related to San Francisco

Other cities in United States

US

New York

46
AQI
PM2.5
10.4μg
PM10
18.2μg
O3
58.3ppb
Good

US

Los Angeles

88
AQI
PM2.5
24.2μg
PM10
44.4μg
O3
62.3ppb
Moderate

US

Chicago

52
AQI
PM2.5
12.3μg
PM10
22.1μg
O3
54.4ppb
Moderate

Compare San Francisco air quality with

San Francisco air quality - frequently asked

Is the air quality in San Francisco safe right now?

San Francisco currently has an AQI of 48, classified as Good. Air quality is good - safe for everyone.

What is the PM2.5 level in San Francisco?

PM2.5 in San Francisco is currently 10.7 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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