Air quality in Ann Arbor, Michigan, United States of America today

Mr. Duck’s Air Quality Score

Unhealthy for sensitive groups for Ann Arbor, Michigan, 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 Ann Arbor, Michigan is classified as USG today. The primary pollutant identified is PM2.5 (fine particles), with a measured concentration of approximately 40.96 µg/m³ based on twelve valid observations reported through OpenAQ.

Data for this assessment come from a set of twelve recent measurements, and no other pollutants are highlighted for the current period. 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

Ann Arbor’s OpenAQ feed currently includes five measured pollutants: PM2.5, PM1, relative humidity, temperature and particle count (UM003). The dataset is drawn from 16 rows of sensor readings, but only 11 distinct stations are represented; the remaining rows lack a clear station identifier or are marked as unknown. All values were last updated on 2026-02-11 at 01:00 UTC, so the freshest timestamp for each pollutant is the same moment.

The PM2.5 observations show a wide spread, with a minimum of 9.39 µg/m³, a median of 29.42 µg/m³ and a maximum that tops 3,583 µg/m³. The 10th‑percentile sits at about 13.11 µg/m³ while the 90th‑percentile reaches roughly 2,445 µg/m³, indicating occasional very high spikes alongside generally lower background levels. By contrast, PM1 is reported from a single sensor and all three statistics (minimum, median and maximum) are identical at 23.44 µg/m³, reflecting no observed variation in the current sample.

Relative humidity, temperature and UM003 each come from one measurement point as well, with values fixed at 49.88 % relative humidity, 8.05 °C temperature and 929.86 particles/cm³ respectively. Because these three parameters have only a single reading, their reported ranges are effectively zero, limiting insight into city‑wide conditions for those variables.

Overall the dataset provides recent timestamps but uneven coverage: PM2.5 benefits from multiple rows and shows substantial variability, while the other four pollutants rely on a solitary sensor each. Consequently, city‑wide assessments for humidity, temperature or particle count should be treated with caution, as conditions can differ across neighborhoods and times not captured in this limited snapshot.

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 dataset for Ann Arbor includes twelve valid measurements and was updated today (2026‑02‑11T01:00:00+00:00). These values represent a snapshot of conditions at the time of collection; air quality can differ across neighborhoods and change throughout the day, so this information reflects only the specific moment captured by the monitoring network.

OpenAQ station rows