Question 1

What is the current AQI in San Francisco?

Accepted Answer

TrueAQI provides real-time ground-sensor Air Quality Index (AQI) telemetry for San Francisco, tracking PM2.5, PM10, NO2, SO2, Ozone, and live weather conditions refreshed continuously.

Question 2

What AQI level is considered unhealthy?

Accepted Answer

An AQI between 101–200 is Poor / Moderate, 201–300 is Unhealthy, 301–400 is Very Poor / Severe, and 401–500+ is Hazardous. Sensitive groups should wear N95 masks when AQI exceeds 150.

Question 3

What is the main pollutant in San Francisco?

Accepted Answer

In most urban centers including San Francisco, fine particulate matter (PM2.5) is the primary air pollutant responsible for the highest AQI sub-index.

Question 4

How is TrueAQI data calibrated?

Accepted Answer

TrueAQI calibrates continuous optical and gravimetric ground sensors against official standards (CPCB India NAQI, US EPA, EU CAQI, and China MEP) with local temperature, humidity, and atmospheric pressure compensation.