Whistler's Green, Alta and Alpha Lakes have become skaters’ paradise over the last week, thanks to near-perfect ice conditions.
Locals and visitors alike have flocked to the frigid expanses. To explain the science behind all the buzz, Pique spoke with Nick Collins, a limnologist, or lake researcher, from the University of Toronto. He’s also a member of the Whistler Lakes Conservation Foundation and provided clarity on exactly why Whistler’s well-known lakes froze the way they did.
“Heavy snowfalls weigh the ice down enough that it forms cracks on the surface and applies downward pressure. Water rises near the shore and floods through the cracks, flowing under the snow, forming a slush layer that will eventually freeze and roughen the ice surface, even if the snow on top blows off," Collins said. "I think the lack of precipitation this winter is probably the major reason for the smooth freeze."
However, Green, Alpha and Alta aren’t the only frozen lakes in Whistler, but their ice is drastically better than Nita and Lost Lake.
“Lost and Nita are two small lakes and they both are in steep-sided basins," Collins said. "Their small size and lack of wind means when they cool at night by radiation and evaporation, it’s just the surface that cools. There's no wind to mix cooled surface water in with the water underneath. They become the first to freeze."
Since they froze in December and retained ice and snowfall on top, their ice surface is rough.
@piquenewsmagazine Green Lake in Whistler is ✨pristine✨ for skating, with 200 hectares of smooth, snow-free ice surrounded by mountain views. Watch this video shot by Marc Stulken Jan. 24, 2025. Stay tuned on Pique Newsmagazine’s website for the science behind what makes ice like this a rarity in Whistler. #whistler #greenlake ♬ original sound - Pique Newsmagazine
Climate change and Whistler’s lakes
Despite the near-perfect ice conditions, locals who monitor lake freezing said the freeze-up on Green and Alpha are much later than normal.
“Freeze-up time data is spotty but this year's is way late for at least Green and Alpha based on data or memories of long-term residents,” Collins said.
Historically, by Christmas and New Year's, people are out skating. But with a warming climate, Whistler and North American lakes are experiencing later-than-normal freezing and earlier melting, according to the British Columbia Lake Stewardship Society (BCLSS).
BCLSS’ Lake Stewardship manual notes “some of the most pervasive and concerning consequences of climate change on lakes include the loss of ice cover.”
By 2050, ice will melt “10-30 days earlier across the Northern Hemisphere,” and climate change’s impacts are felt already, with 19 fewer days of ice on average per century.
Collins said ice record data in Whistler is spotty, but records exist for Alta Lake and were compiled for the Resort Municipality of Whistler’s 2023 Ecosystems and Species Monitoring Program. Using 33 winters of freezing and thawing data from 1942-43 to 1975-76, and comparing it to 21 winters since 2001, a clear trend exists.
Alta freezes seven days later in the 21st century and thaws 17 days earlier, and the number of total ice days have shrunk by 27 days.
Safety concerns
While the views are pristine, ice can still be dangerous. Sea to Sky RCMP for Whistler and Pemberton are reminding residents and visitors to stay safe while having fun.
The Whistler Fire Fighters Professional Association was out conducting ice rescue training Jan. 23, and provided helpful information on Facebook about how thick ice should be to support weight.
Ice that’s less than three inches thick is too thin to support anyone, while four or more inches is safe for walking and skating. At between five and seven inches, ice can bear the weight of a snowmobile or ATV. For people driving vehicles on ice, ice eight to 12 inches is safe for small cars, and medium-sized trucks require 12 to 15 inches of ice thickness.
