Here's what climate change is doing to Canada's 'White Christmas'

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If you live in Charlottetown, Fredericton or Sarnia and you're dreaming of a white Christmas – or Hanukkah, or Kwanzaa – keep dreaming.

There have always been places in Canada where snow in December is rare, such as the south coast of British Columbia, but even traditionally snowy cities are seeing increasingly snow-free holidays as the climate heats up.

Between 1960 and 1984, Charlottetown had a 92 per cent chance of seeing snow on Dec. 25. That probability dropped to 52 per cent during the period between 1997 and 2021.

Fredericton went from an 88 per cent chance of snow on the ground Dec. 25 between 1960 and 1984, to a 44 per cent chance between 1996 and 2021. In Sarnia, Ont. the likelihood of snow on the ground Dec. 25 was 84 per cent between 1960 and 1984. Between 1996 and 2021, it was 36 per cent.

These are just some of the numbers Environment and Climate Change Canada's senior climatologist, David Phillips, crunched for CTVNews.ca in an effort to see how much of a toll climate change has taken on the snowy holidays many Canadians dream about.

"I think one of the real indications of the changing climate right to our face…is the fact that we will see greener Christmases, and also Christmases that have less deep snow," Phillips told CTVNews.ca in a telephone interview on Nov. 17.

"In certain parts of Canada, we're losing that vision of past Christmases. Where (snow) used to be a reality, it's more just sort of a dream."

Climate change is causing average temperatures around the globe to rise, and Canada is warming twice as fast as the rest of the planet, according to the 2019 Canada’s Changing Climate report. The report, commissioned by Environment and Climate Change Canada, found that annual average temperatures in Canada have increased by 1.7 degrees, or 2.3 degrees in Northern Canada, since 1948.

If 2.3 degrees doesn't seem like a major increase, a bit of context might shift your perspective.

"From a climate point of view, two-and-a-half degrees difference is like half the difference in temperature between when the last ice age was here, and then when it wasn't," Phillips said. "So it's huge, from a climatological point of view."

To measure the effect rising temperatures have had on holiday snowfall in Canada, Phillips looked at data gathered at 44 weather stations located across the country during two 25-year periods – 1960 to 1984 and 1997 to 2021.

On average, Canadian cities and towns have seen a 13 per cent decrease in the likelihood of a snowy Dec. 25, from 79 per cent between 1960 and 1984 to 66 per cent between 1997 and 2021. However, that decrease isn't spread evenly across the country.

While parts of the prairies and northern locations such as Iqaluit, Yellowknife and Whitehorse have recorded little-to-no change in the likelihood of a snowy December, communities on Canada's East Coast have recorded some of the biggest differences in the country. Snowy holidays have also become increasingly rare in southern Ontario, southern Alberta and British Columbia.

London, Ont., had an 80 per cent chance of snow cover on Dec. 25 from 1960 to 1984. That probability dropped to 48 per cent between 1997 and 2021.Kelowna, B.C.'s probability dropped to 56 per cent from 76 per cent in the same periods, and Medicine Hat, Alta.'s dropped to 52 per cent from 72.

Not only are snowy winter holidays becoming rarer, but the depth of snow on the ground is thinning out as well, Phillips said.

Stick a ruler into Canada back in the 1970s and on Christmas morning, it would often say 15 or 16 (centimetres), whereas now it's more like 10 or 11," he said. "So we have lost that frequency and also the amount of snow. But again, it's very regionally biased."

Statistically, Timmins, Ont. and Quebec City were still both more than 90 per cent likely to see snow on Dec. 25 as of 2021. But the average depth of that snow had decreased by 22 and 19 centimetres respectively compared to between 1960 and 1984.

Most of the weather stations Phillips collected data from have observed a similar trend, to a lesser extent. For example, Fredericton measured an average snow depth of 21 centimetres on Dec. 25 between 1960 and 1984. Between 1997 and 2021, that depth had thinned to six centimetres.

So how will Canadians experience winter as temperatures continue to rise? For one thing, Phillips said, it will start later and end earlier.

"We are a snowy country, and climate change will still make a snowy and cold country, it's just that the season will be different, it'll be shorter," he said. "So winter may start in mid-January, as opposed to now, and maybe end in early March."

Additionally, less snow doesn't mean less precipitation. It just means more mixed precipitation, including rain, freezing rain and sleet. Phillips said this could have financial implications for winter recreation industries in the most affected areas of the country, as well as for any farmers and gardeners who rely on snow to insulate their crops and gardens.

You'll have more winter rain than snow," Phillips said. "For example, you won't see a ski industry in southern Ontario – unless they can make snow, that'll be their saving grace."

Culturally, a growing number of Canadians will need to adopt a new vision of the holidays that doesn't include dashing through the snow, hearing the snow crunch or building a snowman in the meadow and pretending he's Parson Brown.