A blast of wintry weather has forced a snow squall warning by Environment Canada on Tuesday.

The weather agency says to expect anywhere from 15 to 25 centimetres of snow to fall over the next 24 hours throughout the region.

Environment Canada says what's particularly unusual is how cold it is, with temperatures plummeting about 12 degrees below normal.

The temperature in Barrie reached a high of minus 7 on Tuesday, beating a record of minus 3 set on this day in 1921.

There were whiteout conditions in Wasaga Beach with winds gusting above 50km/h. The town could see another 30cm of snowfall overnight.

Areas under the snow squall warning on Tuesday include:

  • Barrie;
  • Collingwood;
  • Hillsdale;
  • Midland;
  • Coldwater;
  • Orr Lake;
  • Innisfil;
  • New Tecumseth;
  • Angus;
  • Owen Sound and
  • Blue Mountains

"Prepare for quickly changing and deteriorating travel conditions," warns the weather agency's website. "Visibility will be suddenly reduced to near zero at times in heavy snow and blowing snow."

Temperatures are forecasted to plummet to minus 18 with the wind chill overnight on Wednesday with a high of minus four during the day.

The snow squalls will taper off by Wednesday afternoon as the winds shift to the southwest, states Environment Canada.