Outdoor
Current values look suitable for ordinary outdoor activity for most people.
Why: Low AQI and low pollutant levels support this guidance.
San Francisco, California, United States
San Francisco air quality today
Current values look suitable for ordinary outdoor activity for most people.
Data: Hourly Open-Meteo model estimateThe latest update is older than expected, so this page is showing an estimate for the current hour.Detailed metrics and guidance use the latest available detailed data.
Practical guidance
Running
Current values look suitable for an easy outdoor run.
Why: Low AQI and low pollutant levels support this guidance.
Ventilation
Current values support brief ventilation.
Why: Low AQI and low pollutant levels support brief ventilation.
Air quality and outdoor metrics
US AQI
Air Quality Index
50
Good
PM2.5
Fine particulate matter
11.5µg/m³
Moderate
PM10
Coarse particulate matter
14.5µg/m³
Low
NO₂
Nitrogen dioxide
20µg/m³
Low
O₃
Ozone
54µg/m³
Low
UV index
Sun exposure level
1
Low
Temperature
Air temperature
16°C
Comfortable
Feels like
Apparent temperature
14°C
Comfortable
Wind
Wind speed
11km/h
Light
Humidity
Relative humidity
60%
Comfortable
Share page
Disclaimer
This information is a general estimate only and is not medical advice.
Location
San Francisco, United States
Coordinates: 37.7749, -122.4194 · America/Los_Angeles
Interpret AQI for outdoor activity
Calculic's European AQI calculator assesses the value using your population group and planned activity intensity.
Interpret AQI in CalculicThis page's European AQI value, city and timestamp are passed to the calculator through the link.
What affects air quality in San Francisco
At the Air District's Arkansas Street site in San Francisco, the network plan says the westerly sea breeze often disperses pollution, while light winds and surface inversions can raise ozone precursors or particle concentrations.
This is the network plan's neighborhood-scale description of one Potrero Hill-area site, not a citywide rule or current condition.
Local monitoring and context
The San Francisco Arkansas Street station is a neighborhood-scale site that measures ozone, nitrogen oxides, carbon monoxide, PM10, PM2.5 and air toxics.
The listed pollutant coverage applies to the Arkansas Street station and does not mean it represents every San Francisco neighborhood or this page's current AQI.
City air quality FAQ
How should I read the AQI for San Francisco?
US AQI condenses air quality into one value. On this page, it helps you quickly judge whether conditions look good, moderate or more polluted than usual.
Is the air quality good for going outside?
Check the outdoor and running cards first. They combine AQI, particles, ozone, weather and other factors that can affect outdoor comfort.
Should I ventilate right now?
The ventilation card considers AQI and pollutants such as particles, nitrogen dioxide and ozone. If values are elevated, a shorter opening or a later moment may be better.
Why can air quality change during the day?
Weather, emissions, ozone formation, particles and air flow can shift local conditions, so the next hours can differ from the current reading.
Sources and methodology
Current data
This page uses US AQI.
Current and hourly air-quality values are CAMS-based model estimates, not measurements from a local monitoring station. They may not reflect street-level conditions.
- Displayed state
- This hour's model estimate
- Data time
- 31 Oct 2026, 10:00 am
- Weather data
- Open-Meteo
- Air-quality model data
- Copernicus Atmosphere Monitoring Service (CAMS). Open-Meteo selects data suited to this location. Possible CAMS datasets: CAMS European air quality forecasts, ENSEMBLE data; CAMS global atmospheric composition forecasts.
- Licence
- CC BY 4.0
City Air Quality selects the active data package, combines weather and air-quality data, chooses the current or latest usable model value, and formats it for this page.
The latest update is older than expected, so this page is showing an estimate for the current hour.
Detailed metrics and guidance use the latest available detailed data.
Evergreen city statements
Each local statement is linked to a checked primary-authority source. A source check is editorial provenance and does not describe current-data freshness.
Local sources support the background claims below; they are not the source of the current data shown above unless explicitly stated otherwise.
Authoritative sources for local statements
2022 Annual Air Monitoring Network Plan
Bay Area Air Quality Management District
- Scope
- San Francisco
- Source checked
- 23 Aug 2026
PDF pages 122–123, Tables 4.51–4.52, identify the site's setting, dispersion factors, spatial scale and pollutant instruments.
Applicability: The source describes the Arkansas Street station at neighborhood scale; it is not a current citywide reading or this page's provider.
Based on this source: At the Air District's Arkansas Street site in San Francisco, the network plan says the westerly sea breeze often disperses pollution, while light winds and surface inversions can raise ozone precursors or particle concentrations.
The San Francisco Arkansas Street station is a neighborhood-scale site that measures ozone, nitrogen oxides, carbon monoxide, PM10, PM2.5 and air toxics.