What is the air quality trend in San Francisco?

Over the past 8 days, San Francisco had an average AQI of 61 based on station measurements. The worst day was 2026-09-23 with AQI 74.

How is San Francisco air quality measured?

Air quality in San Francisco is measured by ground-level monitoring stations that report PM2.5 and PM10 concentrations hourly. CERNS.IO aggregates readings from nearby stations and converts PM2.5 to the US EPA Air Quality Index (AQI) scale.

Air Quality History for San Francisco, Philippines

Name: San Francisco Air Quality History
Creator: CERNS.IO
License: https://creativecommons.org/licenses/by/4.0/

Historical PM2.5 and AQI trend from monitoring stations near San Francisco, Philippines.

Current AQI
Moderate CAMS model

48 Hours 7 Days 14 Days 20 Days

CSV JSON

Air Quality Index Station

162h

PM2.5 Station

162h · 1 station

Temperature GFS model

28pt

Precipitation GFS model

mm/day

Daily Summary Station

Date	AQI	Range	PM2.5 avg	Hours	Stations
2026-09-23	74	59–85	23.2 µg/m³	9h	1
2026-09-22	65	42–93	19.1 µg/m³	24h	1
2026-09-21	59	36–80	16.5 µg/m³	24h	1
2026-09-20	66	30–95	19.9 µg/m³	24h	1
2026-09-19	66	25–141	20.4 µg/m³	24h	1
2026-09-18	50	14–104	13.9 µg/m³	22h	1
2026-09-17	53	16–131	15.4 µg/m³	22h	1
2026-09-16	59	46–85	16.0 µg/m³	13h	1

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