San Francisco: Air Pollution Today — AQI Index, PM2.5/PM10, Smog Alerts and Forecast

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Latest air quality data: San Francisco

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Pollution and air quality forecast for San Francisco. Today is Thursday, August 27, 2026. The following air pollution values have been recorded for San Francisco:

particulate matter (PM2.5) dust - 7 (Good)
particulate matter (PM10) suspended dust - 10 (Good)
ozone (O3) - 38 (Good)
nitrogen dioxide (NO2) - 9 (Good)
sulfur dioxide (SO2) - 1 (Good)
carbon monoxide (CO) - 114 (Good)

Real-time Air Quality Index (AQI) for San Francisco, Wednesday, August 26, 2026: 1.

AQI 1 Good

What is the air quality in San Francisco today? Is the air polluted in San Francisco?. Is there smog?

Today (Wednesday, August 26, 2026) air quality is good. The air quality has no effect on health. Everyone can continue their outdoor activities normally in San Francisco.

What is the current level of PM2.5 in San Francisco? (particulate matter (PM2.5) dust)
Today's PM2.5 level is: 7 (Good) For comparison, the highest level of PM2.5 in San Francisco in the last 7 days was: 10 (Wednesday, August 19, 2026) and the lowest: 6 (Monday, August 24, 2026).

What is the level of PM10 today in San Francisco? (particulate matter (PM10) suspended dust)
The current level of particulate matter PM10 in San Francisco is: 10 (Good)

How is the O3 level today in San Francisco? (ozone (O3))
38 (Good)

How high is the level of NO2? (nitrogen dioxide (NO2))
9 (Good)

What is the level of SO2 pollution? (sulfur dioxide (SO2))
1 (Good)

How high is the CO level? (carbon monoxide (CO))
114 (Good)

Current data Wednesday, August 26, 2026 at 6:00 PM

PM2,5 7 (Good)

PM10 10 (Good)

O3 38 (Good)

NO2 9 (Good)

SO2 1 (Good)

CO 114 (Good)

Data on air pollution from recent days in San Francisco

index	2026-08-26	2026-08-25	2026-08-24	2026-08-23	2026-08-22	2026-08-21	2026-08-20	2026-08-19
pm25	7 Good	7 Good	6 Good	7 Good	6 Good	6 Good	7 Good	10 Good
pm10	10 Good	10 Good	9 Good	10 Good	9 Good	9 Good	10 Good	14 Good
o3	42 Good	51 Good	53 Good	35 Good	40 Good	48 Good	42 Good	55 Good
no2	9 Good	7 Good	6 Good	7 Good	5 Good	5 Good	5 Good	5 Good
so2	1 Good	1 Good	1 Good	1 Good	1 Good	1 Good	1 Good	1 Good
co	111 Good	107 Good	96 Good	97 Good	99 Good	99 Good	93 Good	101 Good

data source »

San Francisco

Wednesday, August 26, 2026 at 6:00 PM

PM2,5 6.9 (Good)

particulate matter (PM2.5) dust

PM10 10 (Good)

particulate matter (PM10) suspended dust

O3 38 (Good)

ozone (O3)

NO2 8.9 (Good)

nitrogen dioxide (NO2)

SO2 0.7 (Good)

sulfur dioxide (SO2)

CO 114 (Good)

carbon monoxide (CO)

San Francisco

index	2026-08-19	2026-08-20	2026-08-21	2026-08-22	2026-08-23	2026-08-24	2026-08-25	2026-08-26
pm25	9.9	7	6.1	6	7	6.1	7	6.9
pm10	14	10	9	8.9	10	9.1	9.8	9.9
o3	55	42	48	40	35	53	51	42
no2	5.5	5.2	4.5	5.1	6.8	5.6	6.6	8.6
so2	0.99	1.2	0.88	0.96	1.1	1	0.95	0.79
co	101	93	99	99	97	96	107	111

* Pollution data source: https://openaq.org () The data is licensed under CC-By 4.0

🌦️ Weather · 16-day Forecast — United States

16-day weather forecast for United States: today around 30°C (rain), lows near 19°C. Daily temperature and conditions, updated every day. Strong wind (about 25 km/h) is actively clearing smog and dust away.

☀️ UV Index · 16-day Forecast — United States

The UV index in United States today is 7.3 (high) — unprotected fair skin can burn in about 25 minutes.

📍 Air quality in nearby cities

Live PM2.5 around San Francisco — compare nearby locations.

New York City 20 µg/m³
Los Angeles 30 µg/m³
Chicago 10 µg/m³
Houston 15 µg/m³
Philadelphia 12 µg/m³
Phoenix 7 µg/m³
Bronx 20 µg/m³
San Antonio 12 µg/m³

Frequently asked questions

Is the air safe to breathe in San Francisco today?

The current average PM2.5 across San Francisco is about 7 µg/m³, rated “Good”. Air quality is good — outdoor activities are fine for everyone.

What is the current PM2.5 level in San Francisco?

Right now PM2.5 in San Francisco averages about 7 µg/m³ (“Good”). PM2.5 are fine particles small enough to reach the lungs and bloodstream.

Which day last week had the worst air in San Francisco?

Over the past week, the highest daily PM2.5 in San Francisco was recorded on Wednesday, August 19 (about 10 µg/m³).

What is the UV index in San Francisco today?

The UV index in San Francisco today is 7.3 (high) — unprotected fair skin can burn in about 25 minutes.

Does today's wind help disperse smog in San Francisco?

Strong wind (about 25 km/h) is actively clearing smog and dust away.

How is air quality measured?

Air quality here is based on PM2.5 — the concentration of fine particulate matter in µg/m³. Lower values mean cleaner air. Data is updated daily from Open-Meteo.