A relatively balmy Thursday morning will give way to a frigid Thursday evening, prompting the city to issue a cold weather alert that will activate extra services for the city's most vulnerable.

The day will start out at 3 C, with a mix of sun and clouds. By night, the temperature will plummet to -15 C, with snow flurries possible.

Colder weather will continue on Friday, with temperatures expected to hit -8 C during the day and -14 C at night.

As a result of the alert, a warming centre at Metro Hall will open at 7 p.m, additional shelter beds will be made available, and an overnight outreach team will be out helping the city's homeless get to shelters.

Torontonians are reminded to dress warmly in layers, avoid getting wet, and check in on vulnerable friends, family and neighbours.