Chief meteorologist Chris Scott says there should generally be snow on the ground in many areas from the Prairies to the Maritimes as presents are unwrapped Thursday morning.
But he says those in southern Ontario, the Vancouver area, as well as parts of Quebec and the Maritimes will be on the "fringe of the snowpack" and can expect conditions that aren't fit for tobogganing.
Scott says much of southern Ontario is due to see a green or a "brown Christmas" instead as snow melts under the rain and wind of a storm system moving from the U.S., while B.C.'s Lower Mainland will also be seeing green.
He says there should be fresh snow on B.C. ski hills and in the province's interior, along with parts of the prairies including Calgary, southern Saskatchewan and Winnipeg and also northwestern Ontario.
Scott says the mild conditions much of the country has seen in recent weeks will change as the run-up to New Year's Eve brings cold and wintry conditions east of the Rocky Mountains.
"When you look at the country as a whole geographically the vast majority — 90, 95 per cent — is covered in snow and will be Christmas morning. But when you look at the population it's a different story," he said in an interview Sunday.
The timing of the storm system will determine conditions in central and eastern Canada, Scott said.
"We're considering right now that there's a reasonable chance that there's enough snow on the ground Christmas morning to call it a white Christmas, but it will feel unlike a typical white Christmas in that we'll be seeing a lot of rain falling Christmas Eve and through the night."
Scott said those looking to dash outside to try out Christmas presents like toboggans are likely to be disappointed. "It's not going to be very fun even if there is snow on the ground."