Make sure you leave enough room under your Halloween costume for a parka, Grade 4-style, if you plan on going outside this year.

Cold, snowy weather is very much a possibility for Toronto on October 31, according to meteorologists, as what's left of super typhoon Hagibis makes its way across the Pacific Ocean and throws much of Canada into a weeks-long cold snap.

Weather Network meteorologist Dr. Doug Gillham says that we'll see a cooling pattern shape up over the next two weeks in Ontario and Quebec specifically.

"The final week of October and into early November will bring an extended period of colder than normal weather to the Great Lakes region, including southern Ontario" said Gillham in a report published Friday. 

"This pattern will bring the potential for lake-effect snow in the snow belt areas before Halloween."

Gillham calls the potential snowfall "significant," suggesting that he isn't talking about light flurries.

Things could always change  — such is the nature of weather — but you may want to opt for a costume that works with warm boots, just in case. 

On the bright side, we've got a warm weekend ahead with temperatures expected to reach at least 20 C by Monday. This will almost definitely be the last time thermometers display readings above the teens for some time, so enjoy it.