One Quebec town was evacuated Tuesday and a second was put on high alert as flooding caused by unseasonably warm weather continued to threaten the Montérégie and Beauce regions.

Several Quebec rivers are at risk of flooding, including: Châteauguay River Richelieu River Yamaska River Saint-François River Bécancour River Nicolet River Trout River

Civil security authorities ordered residents in the Beauce town of Vallée-Jonction to leave their homes Tuesday after a nearby river spilled over its banks because of rising water levels caused by melting snow and rain.

In Huntingdon, southwest of Montreal, the Trout River overflowed in the town's Hinchinbrooke sector, but no homes have been flooded yet, said Mayor Stéphane Gendron.

But as many as 200 homes and Huntingdon's downtown sector could be flooded if water levels rise overnight, when some 12 mm of rain are expected to fall, Gendron warned.

The town is on evacuation alert and people should be ready to leave on a moment's notice, he said.

Quebec's Beauce and Montérégie regions are dealing with overflowing rivers caused by warm weather.
(Radio-Canada)

"Maybe clear your basement, and be ready to be evacuated, because our fire chief will start distributing evacuation notices [as soon as] this afternoon," Gendron told CBC News.

Canadian Coast Guard workers were dispatched Tuesday to break up ice clogging the Chateauguay River, which rose by 81 centimetres between Monday and Tuesday morning.

But the nearby town is waiting to see what happens over the next 24 hours, said Mayor Sergio Pavone.

"This is a very calm situation. There is no emergency situation right now. We're in surveillance mode," he said.

Flooding can happen every year and being prepared is the best defence, said Frederick Nicole, who owns a pub on the Chateauguay River shore.

"We're getting used to it," he said Monday afternoon. "We always have our pump ready, so when the water's coming, we start the pump — every year it's like that."

Huntingdon residents are on evacuation alert because the Chateauguay River is swollen with melted snow.
(Radio-Canada)

Rising water levels in Trout River forced transport officials to close part of Highway 138 near Godmanchester.

Quebec's civil security agency is watching several rivers south of the Saint-Laurent Valley in the wake of this week's warm snap.

Environment Canada forecast above average temperatures as high as 10 C on Tuesday and Wednesday, with rain for most of southern Quebec.

Air travel bogged down by fog

The warm weather brought in thick fog that has caused several delays and cancellations at Montreal's Trudeau International Airport.

A second fog warning on Tuesday is making it difficult for backlogged flights to get out on time, airport authorities said.

As many as 117 flights were cancelled Monday night when Environment Canada issued its first fog warning this week.

People planning to travel on Tuesday should check the airport website for updated information about their flights, said a spokeswoman at the Aéroports de Montréal.

With files from the Canadian Press