Smoke from wildfires in northern Quebec in Canada covered the city of Montreal in smog on Sunday. It led to the city’s air becoming the world’s most polluted, according to an air quality index.

Ozone is a gas comprised of three oxygen (O3) atoms. It is unstable and reacts easily to other gases. In its natural state, it is a component in several levels of the atmosphere. At high altitudes ...

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New York City recently saw a drop in traffic and an increase in transit ridership after its pricing came into effect.

UPDATE, January 21, 2025: Just after the arrival of the polar vortex in Montreal, a major power outage ... Sunday and Monday will be the coldest air of the season for much of Quebec.

The skies will be mostly cloudy. The low will be -16°. Good air quality (0-50) Primary pollutant PM2.5 6.1 μg/m³ Amount of moisture present in the air relative to the maximum amount of moisture ...