On Tuesday it wasn't just cold. It was cold with snow - making the morning commute a test of patience for many drivers and public transportation users.
The city has issued an extreme cold weather alert and temperatures are not expected to start rising until the end of the week, at the earliest.
The alert allows the city to free up more shelter beds and take extra steps to help the homeless and other vulnerable people.
The CBC's Claire Martin reported on Tuesday evening that, with the wind chill, Toronto hit -21 C. And overnight the temperature is expected to dip to somewhere between -17 to -19 C, much colder if the wind picks up.
Some people said the previous weeks of warm weather meant they were caught off guard.
But others said "this is what it's all about, c'mon be Canadian!"
But medical experts are warning to be careful when the temperature drops — and watch for signs of frost bite.
"Tingling sensations in any of your extremities, or notice any white waxy spots that's a clear indication of frost bite," said EMS dispatcher Jeff Murphy.
Most of the calls the EMS people get during these cold spells deal with "slips and falls, cold exposure calls, car accidents," said Murphy. "People need to ensure they're driving safely when the weather's changing from cold to snowing."
At schools across the city teachers keep an eye on the weather and sometimes have to change recess plans.
"Rest assured if it gets very cold, we're keeping a close eye on our students. If need be, we'll keep them in," said Ryan Bird Toronto District School Board spokesperson.