Bundle up, buttercup, because temperatures are plummeting across Southern Ontario and it's going to get painful.

Multiple weather alerts are currently in effect for the City of Toronto as heavy lake-effect snow and severe cold winds rip through the region, threatening to leave behind as much as 30 cm of the white stuff by Thursday morning.

Toronto's Medical Officer of Health, Dr. Eileen de Villa, issued an extreme cold weather alert for the city early Wednesday morning that will remain in effect until further notice.

Such alerts are always issued when temperatures are forecast to reach -15 C or colder, or when the wind chill is expected to be colder than -20 C.

Toronto's Medical Officer of Health has issued an Extreme Cold Weather Alert today for Toronto in anticipation of colder weather conditions coming our way. #CityofTO @TOPublicHealth news release: https://t.co/EXL1vaEafk

— City of Toronto (@cityoftoronto) December 18, 2019

Wind chill values are expected to reach at least -22 C in Toronto on Wednesday night, according to Environment Canada, though Weather Network meteorologists say it could feel closer to -25 around the GTA this evening.

In addition to the cold weather alert, Environment Canada has issued both a winter weather travel advisory and a snow squall warning for the City of Toronto.

"Brief but intense snowfall moving through the area," warns the federal government's weather service.

"Visibility will be suddenly reduced to near zero at times in heavy snow and blowing snow. Be prepared to adjust your driving with changing road conditions."

Snow Squall Warnings for parts of Southern Ontario #onstorm pic.twitter.com/5gpl2bB44S

— Brandon Houck (@HouckisPokise) December 18, 2019

Citizens are being advised to avoid or postpone all non-essential travel until conditions improve.

Strong winds and bitter cold temperatures are expected to persist into Thursday morning, ushering in some of the harshest chill values Toronto has seen so far this season to date.

Fortunately, things are expected to become more mild over the weekend. On Sunday and Monday, we're looking at 4 degrees with nothing but sun in the sky.

Until then, be safe — and smart — when you head outdoors.