Heavy winds and rain swept through Montreal Tuesday afternoon causing power outages, flooding and dozens of flight cancellations and delays at Trudeau International Airport.

The storm hit the island of Montreal at around 3 p.m., as black clouds suddenly covered the sky.

Rain and wind gusts as strong as 90 km/h knocked down trees and caused flooding in some areas.

Dozens of flights at Trudeau airport were delayed by the winds.

City of Montreal officials said traffic lights on some streets around the city were out of order and urged drivers to reduce speed.

Hydro-Québec said that at the storm's peak, there were almost 30,000 homes and business without power — most of them in Laval, Montreal and Montérégie.

One place hard hit by the storm was McGill University, where a convocation ceremony was underway in outdoor tents.

"We were sitting in the tents. All the girls had their makeup done and their hair, and the guys were looking good in their suits when suddenly the wind started picking up. The large metal poles supporting the tents where we were housed started to shake. People started yelling and running out,” said McGill student Sean Coleman.

The tents were evacuated as a precaution, and the convocation was moved indoors.

Environment Canada said that for the Montreal area, the worst was over by 6 p.m. and a severe thunderstorm warning advisory had been lifted.