Air quality in Montreal, Quebec, Canada today

Mr. Duck’s Air Quality Score

Moderate air today for Montreal, Quebec, Canada

⚠️ 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 Montreal today is classified as Moderate. The primary pollutant identified is PM2.5 (fine particles). Measurements show a PM2.5 reference value of 12.0 µg/m³, based on 36 valid observations collected via OpenAQ.

This assessment reflects the current conditions without additional interpretation. 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 dataset for Montreal pulls hourly readings from OpenAQ across 15 monitoring sites, giving a total of 52 recent records. All the standard urban pollutants are represented: carbon monoxide (CO), nitrogen dioxide (NO₂), ozone (O₃), particulate matter of three size fractions (PM1, PM2.5 and PM10), sulfur dioxide (SO₂), relative humidity, temperature and particle count (UM003). The most recent measurements for each pollutant were recorded on 2026‑02‑10 at 22:00 UTC, so the freshest data are no older than three days.

Across the city the concentration values show a fairly wide spread. For PM2.5 the observed range runs from just under 1 µg/m³ to about 27 µg/m³, with a median of roughly 7 µg/m³; the 10th‑percentile sits near 2 µg/m³ while the 90th‑percentile reaches 17 µg/m³. Temperature varies between 1.4 °C and 24.5 °C, medianing around 12 °C, with most readings (10th–90th percentiles) clustered between about 2 °C and 23 °C. NO₂ values are low overall, ranging from 0.0033 to 0.0159 ppm, median 0.006 ppm; O₃ spans 0.016 to 0.038 ppm with a median of 0.025 ppm. Relative humidity is modest, from 18 % up to 34 %, median about 33 %. Particle count (UM003) sits between 159 and 223 particles per cm³, median near 215.

Coverage differs by pollutant: the most complete series are temperature (8 stations) and PM2.5 (16 stations), while SO₂ is only available from three sites. Because some pollutants have fewer recent rows, city‑wide conditions can appear uneven depending on location and time of day. Users should keep in mind that the snapshot reflects a limited set of points rather than a continuous city‑wide picture.

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 reflect 36 valid measurements and are Updated within 3 days, with the most recent values recorded on 2026‑02‑10T22:00:00+00:00. These figures provide a snapshot of Montreal’s air quality at the time of collection; conditions can differ across neighborhoods and may change throughout the day, so local variations are possible.

OpenAQ station rows