Air quality index for Québec, as of (America/Toronto). Values update hourly — see this page for the current reading and hourly forecast. Today's peak: AQI 34 at 15:00 local time.

airindex·today

Air Quality in Québec

Québec has clean air at the moment, AQI 33, and today's forecast peaks no higher than AQI 34. Today's main contributor is ozone, at 75 µg/m³.

Now, Oct 17at 14:00
33Good
Good0–50
Moderate51–100
Sensitive groups101–150
Unhealthy151–200
Very unhealthy201–300
Hazardous301+

By pollutant

  • O₃ ozone · sets the index nowAQI 33
  • PM₂.₅ fine particlesAQI 8
  • PM₁₀ coarse particlesAQI 2
  • NO₂ nitrogen dioxideAQI 1
  • CO carbon monoxideAQI 1
  • SO₂ sulfur dioxideAQI 0
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 Québec · Local time (EDT)

Today, Oct 17
Tomorrow, Oct 18
50
Peak 34 · 15:00
Peak 28 · 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
00:00200.50.5611.21.10.153°
01:00170.40.5621.41.00.152°
02:00190.50.5631.80.90.152°
03:00210.40.5641.60.80.151°
04:00240.40.4641.60.70.151°
05:00260.40.4641.70.70.152°
06:00280.50.5652.10.70.151°
07:00290.50.5662.60.70.151°
08:00300.81.0672.80.70.151°
09:00301.62.3702.40.80.152°
10:00302.43.7731.80.90.153°
11:00312.94.6751.30.90.153°
12:00323.25.2761.10.80.154°
13:00323.35.2761.00.70.154°
14:00332.94.7751.10.60.154°
15:00342.53.9741.30.60.151°
16:00342.33.6721.60.60.153°
17:00342.43.7692.30.70.162°
18:00342.84.1663.70.90.160°
19:00343.34.5625.41.20.170°
20:00333.84.9587.11.50.180°
21:00324.45.5548.61.80.180°
22:00315.16.149102.20.190°
23:00295.46.446112.40.190°
Tomorrow
00:00285.46.345102.30.190°
01:00265.16.1449.32.10.180°
02:00254.85.8448.41.90.180°
03:00234.65.6438.01.80.181°
04:00224.65.5427.81.80.171°
05:00214.55.5408.22.00.181°
06:00204.65.6379.92.40.191°
07:00205.26.233123.00.201°
08:00195.86.832133.50.211°
09:00185.76.835123.80.212°
10:00185.36.3399.04.00.203°
11:00174.85.9446.74.00.204°
12:00184.45.5485.53.90.194°
13:00184.25.3534.83.60.185°
14:00194.05.1564.53.40.186°
15:00204.05.1584.73.30.186°
16:00214.05.0585.33.20.187°
17:00234.14.9576.53.20.196°
18:00245.05.7539.03.40.206°
19:00256.16.847123.60.216°
20:00256.06.744143.70.226°
21:00255.56.245133.40.216°
22:00244.65.149112.90.206°
23:00244.24.6528.62.60.195°

Today at a glance

Worst hour
15:00
peaks at AQI 34
Tomorrow
Clean again, peak 28
peak at 00:00

The week, hour by hour

Tomorrow stays clean as well, with a forecast peak of AQI 28 (good). Every daily peak in the 5-day forecast stays in the good band, from AQI 27 to AQI 50.

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 34 at 15:00
Overcast4° / 0°
SunOct 18
Peak 28 at 00:00
Overcast7° / 0°
MonOct 19
Peak 27 at 17:00
Overcast15° / 2°
TueOct 20
Peak 50 at 12:00
Clear sky14° / 5°
WedOct 21
Peak 45 at 00:00
Clear sky9° / 3°

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
33
PM₂.₅fine particles
8
PM₁₀coarse particles
2
NO₂nitrogen dioxide
1
COcarbon monoxide
1
SO₂sulfur dioxide
0
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: Laval · Terrebonne · Montreal · Lévis · Le Plateau-Mont-Royal

About Québec

CountryCanada, Quebec
TimezoneAmerica/Toronto (UTC-4)
Coordinates46.81° N, 71.21° W
Population≈ 532K

Air quality in Québec — common questions

What is the air quality in Québec right now?

The current air quality index (AQI) in Québec is 33 (Good). Today's forecast peak is AQI 34 (Good) at 15:00 local time, and tomorrow's forecast peak is AQI 28. These values come from the CAMS forecast model, not from a local monitoring station.

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

Today's forecast puts the highest AQI in Québec at 15:00 in the afternoon, reaching 34. 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 Québec tomorrow?

Tomorrow's forecast peak for Québec is AQI 28 (Good) around 00:00 local time, much the same as today's peak of 34. 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 Québec today?

The air quality index in Québec is set by O₃ right now. The modelled level this hour is 75 µg/m³, within the World Health Organization's 2021 guideline of 100 µg/m³. The others follow: PM₂.₅ (AQI 8), PM₁₀ (AQI 2), NO₂ (AQI 1), and CO (AQI 1).
Pollutant levels in Québec at the current hour
PollutantSub-indexLevelWHO 2021Vs guideline
O₃3375 µg/m³100 µg/m³ (8h)0.8×
PM₂.₅82.9 µg/m³15 µg/m³ (24h)0.2×
PM₁₀24.7 µg/m³45 µg/m³ (24h)0.1×
NO₂11.1 µg/m³25 µg/m³ (24h)0.04×
CO10.15 mg/m³4 mg/m³ (24h)0.04×
SO₂00.6 µg/m³40 µg/m³ (24h)0.02×
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 Québec this week?

Over the 5-day forecast, daily peak AQI in Québec rises from 34 to 45. These are peak values: each day still has cleaner and dirtier hours, which the chart above shows. The worst day of the stretch is Tuesday, peaking at AQI 50.

How is air quality forecast for Québec, Quebec, Canada?

Air quality for Québec 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. Québec lies at 46.8° 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.