Snowking's Winter Festival announced it will close during the daytime "due to unseasonably warm weather."
The announcement came as Yellowknife reached a March high of 8C for the first time in 15 years. March 2004 was the last time the city was this warm at this time of year.
This is the first time the festival, held in a castle built out of snow on the frozen Yellowknife Bay, has closed for warm weather in its 24-year history. Organizers explicitly linked the closure to climate change.
The Snowcastle is ordinarily closed on Mondays. From Tuesday until further notice, the castle will not open between 12pm and 5pm.
"This is a temporary measure meant to protect the snow while it is soft," read a news release issued by festival organizers.
Kids' night, from 7pm on Wednesday, is expected to go ahead as usual, as is the Cabin Fever Reliever music show from 9pm on Friday, which features Baby Brian and Megan Nash.
The Snowkademy spring break camp will continue as scheduled each weekday morning for those who have registered.
"I have confidence in my understanding of how snow reacts to excessive heat from Mother Nature,” Snowking Anthony Foliot, the festival's creator, was quoted as saying in the news release.
Organizers said public safety was a priority and the castle structure will be "closely monitored" by those who built it.
Monday's news release stated the festival hopes to reopen once temperatures drop back to normal levels, but there was little sign of immediate relief from the heat in Environment Canada's seven-day forecast.
Yellowknife is projected to experience highs above freezing, and at least 10 degrees above 30-year averages for this time of year, for the rest of the week.
"Closing the Snowcastle for the first time really drives home the impact of climate change,” said Laura Busch, a member of the festival team.
"We are a winter festival held in a winter climate, and up until now have been inviting the public to come play in the snow with us for the whole month of March.
"It’s true there is a difference between one weather pattern and global climate, but this really shows the impact a couple degrees can have."
Last year, the Long John Jamboree – a weekend-long festival which operates next-door to Snowking's Winter Festival – had to close for a day due to high winds. The resulting financial losses threatened its continued operations, and only in late January did Jamboree organizers confirm the event would go ahead this year.
Jamboree volunteers have already expressed concern that forecast warm temperatures could pose an entirely different set of problems this year.
Snowking's Winter Festival staff, in their news release, also alluded to the financial consequences of closing down, even temporarily.
"The Snowking and his team work tirelessly to build and put on the coolest festival around in order to bring joy to the Yellowknife community," the news release stated.
"The financial viability of the festival depends heavily on ticket sales, despite the ongoing and appreciated support of our funding partners and sponsors."