Air quality index for Calgary, as of (America/Edmonton). Values update hourly — see this page for the current reading and hourly forecast. Today's peak: AQI 42 at 20:00 local time.

airindex·today

Air Quality in Calgary

Air quality in Calgary is good right now, at AQI 20, and today's forecast keeps it there — the highest hourly value is AQI 42. Today's main contributor is ozone, at 41 µg/m³.

Now, Oct 17at 06:00
20Good
Good0–50
Moderate51–100
Sensitive groups101–150
Unhealthy151–200
Very unhealthy201–300
Hazardous301+

By pollutant

  • O₃ ozone · sets the index nowAQI 20
  • PM₂.₅ fine particlesAQI 15
  • NO₂ nitrogen dioxideAQI 7
  • PM₁₀ coarse particlesAQI 4
  • SO₂ sulfur dioxideAQI 2
  • CO carbon monoxideAQI 2
Air quality is satisfactory — it's a great day to be active outside

Modeled forecast data. AQI values come from atmospheric models (CAMS via Open-Meteo), not local monitoring stations. Readings can differ from ground-level conditions — for exact street-level values, consult an official air quality station near you. The forecast is calculated for a grid square, roughly 11 km across Europe and 45 km elsewhere, and air quality can vary within one square.

The next 48 hours

Hourly air quality index for Calgary · Local time (MDT)

Today, Oct 17
Tomorrow, Oct 18
50
Peak 42 · 20:00
Peak 39 · 00:00
0:00
6:00
12:00
18:00
0:00
6:00
12:00
18:00

Good ≤ 50

Now
Show hourly data table
TimeAQIPM₂.₅µg/m³PM₁₀µg/m³O₃µg/m³NO₂µg/m³SO₂µg/m³COmg/m³°C
Today
00:00265.15.636275.20.2610°
01:00234.44.840224.50.2412°
02:00213.63.946163.40.2210°
03:00203.23.550122.70.219°
04:00203.13.449112.50.207°
05:00203.03.345112.60.196°
06:00203.03.341133.00.206°
07:00203.33.635204.30.246°
08:00204.75.029285.90.306°
09:00196.46.729326.60.326°
10:00195.66.041265.60.2910°
11:00183.13.661153.70.2316°
12:00192.53.0776.12.20.1718°
13:00211.92.3882.91.40.1618°
14:00231.31.5972.01.00.1616°
15:00261.41.71011.80.80.1614°
16:00301.41.9992.00.80.1614°
17:00341.62.1923.01.00.1613°
18:00381.82.3863.81.20.1611°
19:00412.02.4834.31.40.169°
20:00422.02.4804.71.70.178°
21:00422.02.4785.01.90.178°
22:00422.12.6765.02.00.167°
23:00402.22.6745.02.00.167°
Tomorrow
00:00392.32.7724.92.00.166°
01:00372.42.8694.72.00.165°
02:00362.52.9654.61.90.164°
03:00352.73.1615.22.00.163°
04:00332.83.2576.42.20.161°
05:00323.03.4548.32.60.151°
06:00313.43.948123.50.170°
07:00294.34.837205.50.220°
08:00276.67.124298.10.29-1°
09:00249.19.619349.50.320°
10:00218.48.929298.90.303°
11:00197.37.948197.10.256°
12:00185.46.163115.50.209°
13:00194.24.9727.14.40.1810°
14:00203.74.5794.83.50.1710°
15:00223.74.5814.63.00.1611°
16:00243.64.5776.83.00.1711°
17:00273.74.668113.50.1911°
18:00305.46.258174.10.219°
19:00327.88.647244.90.247°
20:00328.49.234325.80.285°
21:00309.09.724397.10.324°
22:0027101119429.10.364°
23:002412121643110.395°

Today at a glance

Worst hour
20:00
peaks at AQI 42
Tomorrow
Clean again, peak 39
peak at 00:00

The week, hour by hour

Tomorrow looks just as good, peaking at AQI 39 (good). Every daily peak in the 5-day forecast stays in the good band, from AQI 29 to AQI 42.

Each cell is one forecast hour, coloured by air quality band. A ring marks the day's worst hour. The blue ring marks the current hour.

TodayOct 17
Peak 42 at 20:00
Overcast18° / 6°
SunOct 18
Peak 39 at 00:00
Overcast11° / -1°
MonOct 19
Peak 37 at 08:00
Overcast12° / 5°
TueOct 20
Peak 32 at 00:00
Overcast10° / 3°
WedOct 21
Peak 29 at 19:00
Partly cloudy14° / 1°

Pollutants right now

Every pollutant on the same AQI scale as the big number above. The index only ever equals the worst score — pollutants don't add up.

050100150+
O₃ozone · sets the index now
20
PM₂.₅fine particles
15
NO₂nitrogen dioxide
7
PM₁₀coarse particles
4
SO₂sulfur dioxide
2
COcarbon monoxide
2
GoodModerateUnhealthy for Sensitive GroupsUnhealthyVery UnhealthyHazardous

The colors cover a wide area, not a street. The forecast works in squares of roughly 11 km across Europe and 45 km elsewhere, so the air where you actually are can differ from the shade under the city.

Check air quality in: Edmonton · Saskatoon · Spokane · Tri-Cities · Kelowna

About Calgary

CountryCanada, Alberta
TimezoneAmerica/Edmonton (UTC-6)
Coordinates51.05° N, 114.09° W
Population≈ 1.31M

Air quality in Calgary — common questions

What is the air quality in Calgary right now?

The current air quality index (AQI) in Calgary is 20 (Good). Today's forecast peak is AQI 42 (Good) at 20:00 local time, and tomorrow's forecast peak is AQI 39. These values come from the CAMS forecast model, not from a local monitoring station.

When is air quality expected to be worst in Calgary today?

Today's forecast puts the highest AQI in Calgary at 20:00 in the evening, reaching 42. The largest contributor right now is O₃. Air quality shifts through the day with traffic, wind, how well the air mixes and sunlight, so the hourly chart above shows the pattern for today and tomorrow.

What will the air quality be in Calgary tomorrow?

Tomorrow's forecast peak for Calgary is AQI 39 (Good) around 00:00 local time, much the same as today's peak of 42. A next-day forecast is less certain than today's, so check back in the morning for the updated hourly curve.

Which pollutants drive the AQI in Calgary today?

The air quality index in Calgary is set by O₃ right now. The modelled level this hour is 41 µg/m³, within the World Health Organization's 2021 guideline of 100 µg/m³. The others follow: PM₂.₅ (AQI 15), NO₂ (AQI 7), PM₁₀ (AQI 4), SO₂ (AQI 2), and CO (AQI 2).
Pollutant levels in Calgary at the current hour
PollutantSub-indexLevelWHO 2021Vs guideline
O₃2041 µg/m³100 µg/m³ (8h)0.4×
PM₂.₅153.0 µg/m³15 µg/m³ (24h)0.2×
NO₂713 µg/m³25 µg/m³ (24h)0.5×
PM₁₀43.3 µg/m³45 µg/m³ (24h)0.1×
SO₂23.0 µg/m³40 µg/m³ (24h)0.1×
CO20.20 mg/m³4 mg/m³ (24h)0.1×
The overall AQI is the highest of the six sub-indices, so the pollutant with the highest sub-index is the one setting the number shown on this page. Sub-indices are computed over the EPA's averaging periods, while the levels are modelled values for the current hour.

Is air quality improving in Calgary this week?

Over the 5-day forecast, daily peak AQI in Calgary falls from 42 to 29. These are peak values: each day still has cleaner and dirtier hours, which the chart above shows.

How is air quality forecast for Calgary, Alberta, Canada?

Air quality for Calgary is forecast with the Copernicus Atmosphere Monitoring Service (CAMS), operated by ECMWF. CAMS models hourly levels of PM2.5, PM10, ozone, nitrogen dioxide, sulfur dioxide and carbon monoxide. Calgary lies at 51.1° N in the Northern Hemisphere, which sets the seasonal pattern of sunlight that drives much of the chemistry behind these pollutants. AQI values on this page use the US EPA scale.
About the Air Quality Index

What is the Air Quality Index (AQI)?

The Air Quality Index (AQI) is a tool developed by the U.S. Environmental Protection Agency (EPA) to communicate how clean or polluted the air is and what health effects may be of concern. The AQI runs from 0 to 500 and is divided into six color-coded categories: Good, Moderate, Unhealthy for Sensitive Groups, Unhealthy, Very Unhealthy, and Hazardous.

How do I read the AQI values?

Lower AQI values mean cleaner air. An AQI of 0–50 (green) is Good, 51–100 (yellow) is Moderate, 101–150 (orange) is Unhealthy for Sensitive Groups, 151–200 (red) is Unhealthy, 201–300 (purple) is Very Unhealthy, and 301–500 (maroon) is Hazardous. When the AQI exceeds 100, air quality is considered unhealthy — at first for sensitive groups, then for everyone as the AQI rises.

Who are the sensitive groups?

Sensitive groups include people with heart or lung disease, older adults, children and teenagers, people who are pregnant, and people who are active outdoors. These groups are more likely to be affected when air quality is poor. If you are in a sensitive group, you can reduce your exposure by taking fewer and shorter outdoor walks when the AQI is elevated.

Which pollutants are measured?

The AQI covers five major pollutants regulated under the Clean Air Act: ground-level ozone (O₃), particle pollution (PM₂.₅ and PM₁₀), carbon monoxide (CO), sulfur dioxide (SO₂), and nitrogen dioxide (NO₂). An AQI value is calculated for each pollutant, and the highest value determines the overall AQI.

Where does the air quality data come from?

The hourly air quality data comes from the Copernicus Atmosphere Monitoring Service (CAMS), which provides global atmospheric composition forecasts. The data is accessed via Open-Meteo, which provides free, open-source weather and air quality APIs. The AQI categories and health guidance follow the EPA AirNow technical standard (EPA-454/B-24-002).

What are the health effects of poor air quality?

Poor air quality can cause respiratory issues, aggravate asthma and allergies, and increase the risk of cardiovascular problems. Fine particles (PM₂.₅) can penetrate deep into the lungs and bloodstream. The World Health Organization estimates that air pollution causes millions of premature deaths worldwide each year.

How often is the air quality forecast updated?

The CAMS air quality forecast is updated regularly using atmospheric models. Weather data such as temperature and cloud cover comes from Open-Meteo. The forecast provides up to 5 days of hourly air quality predictions.

AQI Levels (US EPA Standard)

Good (0–50) — Air quality is satisfactory — it's a great day to be active outside
Moderate (51–100) — Unusually sensitive people should consider reducing prolonged or intense outdoor activity
Unhealthy for Sensitive Groups (101–150) — Sensitive groups should reduce prolonged or intense outdoor activity. Take more breaks and watch for symptoms such as coughing or shortness of breath
Unhealthy (151–200) — Everyone should reduce prolonged or intense outdoor activity. Sensitive groups should avoid outdoor exertion. Consider moving activities indoors
Very Unhealthy (201–300) — Everyone should avoid prolonged or intense outdoor exertion. Sensitive groups should avoid all outdoor physical activity. Move activities indoors or reschedule
Hazardous (301–500) — Health warning — everyone should avoid all outdoor physical activity. Stay indoors and keep activity levels light. Follow tips for keeping particle levels low indoors

AQI categories and health guidance: EPA AirNow (EPA-454/B-24-002, May 2024). Air quality data: CAMS/Copernicus via Open-Meteo.