WinSport is extending its ski and snowboard hill closure at Canada Olympic Park through Friday as Environment Canada forecasts a high of –23 C and a wind chill that will make it feel like –36 C.

Normal operating hours are expected to resume Saturday and updates will be provided on WinSport's website.

Environment Canada issued extreme cold warnings issued for parts of southern Alberta Thursday morning, where wind chills had made it feel like –40C. 0:22

Meanwhile, ski hills in the mountains west of the city remain open for die-hards this weekend despite the biting conditions.

"It's cold in the morning, but as soon as the sun hits the lifts things get better quickly, especially higher up the hill," said Dan Markham with Lake Louise Ski Resort.

All lifts, lodges and restaurants are open at Lake Louise this weekend and Sunday's Heavy Metal Rail Jam will still go ahead in frigid temperatures. (Nicole Estabrooks)

"By Saturday we'll have 110 runs open, including three newly opened runs on the lower half of the front side. We're also opening some double black diamond terrain on Friday, including Whitehorn 2 Gullies B&C and North Cornice," Markham said.

A Mount Norquay spokesperson said the cold weather is helping them crank up their efficiencies on snow making and build on conditions there.

"We're actually pretty thankful for the cold. This is catch up time for snow making so it's a good thing," said Norquay's director of sales and marketing, Simon Moffat, who noted Norquay's lifts can run into the deep minus 30s, so operations aren't slowing down.

But he said Norquay's ski programs for kids start this weekend and they could be impacted.

"There's a cut-off temperature so we'll have to wait and see if that affects the camps and lessons this weekend," said Moffat.

Zoo Lights cancelled tonight

Away from the hills, the Calgary Zoo is cancelling its Zoolights attraction again Thursday night due to the extreme weather. The event is expected to resume Friday.

Environment Canada ended extreme cold warnings issued for parts of southern Alberta Thursday morning, where wind chills had made it feel like –40 C.