Hold on to your toque.

Toronto is bracing for a blast of freezing weather that will bring the coldest temperatures of the winter season overnight.

The cold weather will start to set in Monday afternoon as the temperature drops to -4 C with strong, chilly winds before plummeting even further overnight  to -16 C without the wind chill. With the wind chill, it will feel more like -25 C.

As a result, the city has issued an extreme cold weather alert, and is advising homeless people to seek shelter during the cold snap. Anyone who sees someone in need of assistance is asked to call 311, the city says. For emergencies, call 911.

During the alert, outreach workers will be speaking to homeless people and urging them to stay indoors at shelters. Shelters are relaxing service restrictions and adding a combined 172 spaces to accommodate more people, and TTC tokens are being handed out at drop-in facilities to provide transportation to shelters.

An alert is issued when Environment Canada predicts a temperature of -15 C or lower without the wind chill, issues a wind chill warning, and/or predicts extreme weather conditions such as a blizzard, ice storm or sudden drops in temperature, the city said.

Because of the looming frigid weather, Environment Canada has issued a special weather statement for parts of southern and eastern Ontario.

Toronto is included in the special weather statement, which advises of cold Arctic air, brisk winds and snow flurries.

Most areas will be whipped by wind gusts up to 60 kilometres-per-hour and be blanketed by up to two centimeters of snow by Monday night.

Beyond Toronto, snow squall warnings are in effect for Grey-Bruce, Barrie, Collingwood, Bracebridge, Gravenhurst, Goderich, London and other communities, where up to 15 cm of snow may fall by Monday night.

Environment Canada said the St. Thomas, Waterloo, Guelph, Orangeville and northern parts of the Greater Toronto Area will receive bursts of heavy snow flurries, resulting in local snowfall amount of five centimeters.

Hazardous winter driving conditions

People in those areas should be prepared to encounter poor visibility on the roads because gusty winds may whip up freshly fallen snow.

Motorists should be prepared for hazardous winter driving conditions, from low visibility and blowing snow to accumulating snow on untreated roads, especially in the regions where snow squall warnings and watches are in effect, Environment Canada said.

The national weather service is urging people to pay attention to their local forecast as the system develops.

Road safety tips

Given the cold weather and potential for hazardous driving conditions, CAA South Central Ontario is offering the following safety tips for motorists:

  • Check the weather forecast
  • Plan your route and give yourself extra travel time
  • Dress for the weather conditions and pack extra clothing
  • Remove all snow and ice from your vehicle
  • Top up your windshield washer fluid
  • Slow down and drive according to the road conditions
  • Leave extra space between you and the vehicle in front of you

In case of an emergency, here's what you should pack in your vehicle, according to CAA South Central Ontario:

  • Ice scraper
  • Snow brush
  • Shovel
  • Booster cables
  • Blankets
  • Extra clothing and footwear
  • Flashlight
  • First aid kit
  • Windshield washer fluid
  • Bottled water
  • Granola or energy bars