As per reports, a smog warning and a freezing rainfall warning have been issued for Montreal on Friday (27 Decemer). High pollution levels, primarily from wood heating, have led to poor air quality in urban areas.

• A major weather system from the Southern US is expected to bring freezing rainfall to the St. Lawrence Valley between Saturday (28 December), evening and Sunday (29 December),, making roads and walkways snowy and slippery.
• Friday (28 December), is forecast to be mainly sunny with a high of minus eleven degrees Celsius, feeling like minus seventeen degrees Celsius with the wind chill. Saturday (29 December), is forecast to see a mix of sunny and cloudy conditions, with a high of minus five degrees Celsius.
• Sunday (29 December), and Monday (30 December), is forecast to bring periods of rainfall and warmer temperatures, reaching highs of three degrees Celsius and eight degrees Celsius, respectively.
• Tuesday (31 December), will feature a mix of sunny and cloudy conditions with a high of 4 degrees Celsius. Tuesday (31 December), night is forecast to be cloudy with a 60 percent chance of light snow and 0 degrees Celsius.