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ACA Air Monitoring On your phone? Mobile view
Click anywhere on the map to identify nearby stations, sensors, and weather

How to read this map

This map shows air quality right now across the Alberta Capital Airshed.

The colours

Every number is the AQHI, the Air Quality Health Index: a score for health risk from air pollution.

1–3Low. A great day to be outside. 4–6Moderate. Most people are fine. If you have heart or lung problems, take it easier outside. 7–10High. Cut back on hard exercise outside, especially if you feel unwell. 10+Very high. Put off hard activity outside. People at risk should avoid it.

What you see on the map

2Big circles are official monitoring stations. The number is the AQHI right now.
Small circles are low-cost PurpleAir sensors. The number is an estimated AQHI (see below).
Shading is our best estimate of the AQHI in the areas between monitors.
Grey means no reading right now.

Click anything to learn more. Tap a section below for how it works.

How the sensors estimate the AQHIThe small circles

PurpleAir sensors measure fine particles, like smoke and dust. But the AQHI also depends on two gases, ozone and nitrogen dioxide, which these sensors can’t measure.

So we combine each sensor’s reading with the ozone and nitrogen dioxide levels in the area, from Environment and Climate Change Canada. Together they give an estimated AQHI for that spot.

We also check each sensor’s readings and leave out ones that look faulty.

It is an estimate, not an official reading.

How the shading fills the gapsThe AQHI grid

Monitors are far apart, so we fill in the map between them. Each small square takes its value from the monitors around it. Closer monitors count more.

  • “Stations” uses official stations only.
  • “Stations + Sensors” also uses the PurpleAir estimates, each counting half as much as a station. This one is on by default.

The shading updates every hour. A dashed outline means one station reads very differently from its neighbours. It could be a real local event or an instrument problem.

The other layersTurn them on with the list at the top right
  • Winds: current wind speed, from Environment and Climate Change Canada.
  • ECCC Alerts: weather alerts from Environment and Climate Change Canada.
  • FireSmoke: a wildfire smoke forecast from FireSmoke Canada (March to October).
Where does this data come from?

Official stations: Alberta’s air monitoring network. Sensors: PurpleAir. Regional ozone and nitrogen dioxide, weather and alerts: Environment and Climate Change Canada. Smoke forecast: FireSmoke Canada. Readings are near real time and have not been through final quality checks. For the official AQHI, check the nearest station.