MONTREAL -- There is a severe thunderstorm watch for the Greater Montreal area, according to Environment Canada.
"Severe thunderstorms can produce tornadoes," the agency states. "Lightning kills and injures Canadians every year. Remember, when thunder roars, go indoors."
Severe thunderstorm watches are issued when atmospheric conditions are favourable for the development of thunderstorms that could result in large hail, damaging winds and torrential rainfall.
Strong wind gusts can move loose objects, damage weak buildings, break branches off trees and overturn large vehicles.
Heavy downpours can cause flash floods and water pooling on roads.
In Canada, lightning kills up to 10 people every year.
Temperature-wise, the mercury is expected to hit 29 degrees Celsius in Montreal on Monday, with a humidex of 37.
By Tuesday, Environment Canada predicts those temperatures will drop to 17 degrees Celsius during the day and 10 degrees Celsius overnight.