Air Quality

Last updated June 9, 2025

The city has adopted various measures to protect air quality. What are the standards set for the population? Which permits are required for corporations? Find out more about the air quality index, report a worrisome situation and monitor smog episodes.

Preventive measures

Montréal enforced regulations meant to preserve air quality and reduce greenhouse gas emissions and intended for both citizens and industries.

Standards for the use of fireplaces and cars

If you own a solid fuel-burning fireplace or stove (wood, ecologs, coal, pellets), your appliance must be declared, comply with regulations and is subject to an installation, replacement or removal permit. If you have an engine-operated vehicle, idling is forbidden.

Solid fuel-burning stoves and fireplaces

Motor vehicle idling

Permits for corporations

Establishments whose activities generate air pollution must hold a permit. To receive one, they must demonstrate compliance with current by-laws and regulations. Once a permit has been granted, samples to measure the amounts of pollutants discharged into the air may be required to verify that regulatory requirements and standards are respected.

Apply for a permit to carry out temporary work

Apply for an Air pollutants discharge permit

Air quality index

The concentration of pollutants in the air is measured regularly at 11 permanent sampling stations and two temporary stations for special projects. The city’s air quality surveillance network publishes the results of its tests in an interactive map (in French). The scientific community can also view the network’s open data (in French) to monitor air quality. The interactive air quality map is temporarily unavailable.

Monitoring air quality in Montréal

Air Quality in Montréal: 2022 Report Card

Reporting an issue

You can report a situation that seems abnormal or suspicious relating to air quality. Complaints are analyzed within 24 working hours. You will be advised of the measures taken.

Report an environmentally harmful event

Smog

Episodes may occur at any time during the year. Main causes include wood burning during winter and brush fires. To receive alerts issued by Environment Canada, download the  WeatherCan app.

Health impacts

Fine particles may affect the population’s health, particularly for at-risk individuals (babies, young children, pregnant women, people over 65 years old, and individuals living with respiratory or heart conditions).

During episodes of poor air quality, it is recommended to:

  • Reduce or postpone outdoor cardiovascular activities

  • Opt for indoor activities

  • Keep windows and doors closed to protect your indoor air quality

  • Set your air conditioners to “recirculation” mode

  • Follow public health recommendations (in French).

Impact on services

A significant drop in air quality may cause certain outdoor activities to be cancelled, and the opening hours of some outdoor municipal facilities may change. Check schedules before you make your way to your planned activities. Sign up for Notices and Alerts to get text messages or emails in case of an unforeseen or emergency situation.

Learn more about the topic