Air quality in Daly City, California, United States of America today

Mr. Duck’s Air Quality Score

Good air today for Daly City, California, United States of America

⚠️ This website is currently under active development. Some data may be incomplete or temporarily inaccurate. For health-critical decisions, please verify information through official government or environmental sources.

Categories follow US EPA AQI breakpoints for PM (estimate from latest valid measurements; this project does not compute EPA NowCast/24-hour AQI yet).

This friendly indicator summarizes the latest city readings. For health guidance, please see: EPA AirNow or WHO.

Air quality today

The air quality in Daly City today is classified as Good. The primary pollutant measured is PM2.5 (fine particles), with a recorded concentration of 7.64 µg/m³ based on ten valid observations reported through OpenAQ.

Overall conditions meet the criteria for a Good rating, and no additional pollutants reached reporting thresholds. This page is informational; for health guidance, use official sources such as EPA AirNow or WHO.

Latest sensor values

PM categories follow US EPA AQI breakpoints, shown here as an estimate derived from the latest valid measurements (this project does not compute EPA NowCast/24-hour AQI yet).

What the data includes

The Daly City air‑quality dataset contains measurements for six pollutants – PM1, PM2.5, PM10, relative humidity, temperature and UM003 (particle count). The data come from two monitoring locations and a total of eleven individual rows. For five of the six parameters the most recent readings were recorded on 2026‑02‑11 at 01:00 UTC, so those values are fresh within the last week. PM10 is an outlier: its only entry dates back to 2025‑01‑13 at 23:00 UTC and is therefore considerably older than the rest of the set.

Across the recent observations the recorded concentrations span a modest range. PM1 varies from about 1.69 µg/m³ up to 2.82 µg/m³, with a median near 2.25 µg/m³; PM2.5 shows a broader spread, ranging from roughly 2.62 µg/m³ to 7.64 µg/m³ and a median of 5.13 µg/m³. Relative humidity stays tightly clustered between 61.4 % and 63.94 %, centering on 62.67 %; temperature is similarly narrow, moving from 14.5 °C to 15.54 °C with a median of 15.02 °C. The particle‑count metric UM003 ranges from about 357.84 to 445.60 particles/cm³, median 401.72.

Because the dataset relies on only two stations, spatial coverage is limited and conditions can differ across neighborhoods. Moreover, the single PM10 record is over a year old, so any current assessment of that pollutant would be uncertain. Overall, most pollutants have recent, consistent data, but the sparse station network and the outdated PM10 entry mean the picture of air quality in Daly City is incomplete and may not capture short‑term or location‑specific variations.

Learn more about sources and filtering: About the data.

Trusted references: WHO (Air pollution) · US EPA AirNow · European Environment Agency (Air)

Latest sensor values (bars)

PM categories follow US EPA AQI breakpoints, shown here as an estimate derived from the latest valid measurements (this project does not compute EPA NowCast/24-hour AQI yet).

Data notes

The data shown for Daly City reflects ten valid measurements and was updated today (last refreshed at 2026‑02‑11T01:00:00+00:00). While this snapshot provides a current view of ambient conditions, air quality can differ across neighborhoods and change throughout the day, so values may not represent every location or moment within the city.

OpenAQ station rows