Cold Weather Closure
The cutoff temperature for not opening is -25C at the top of the hill. You can consult that temperature in the header of the Mount Sima website. If you click on the link, you will have access to the past and current weather station data.
To know if the hill will be open, call the Snow Line at 867-667-7547. It is updated around 7 AM.
There is a happy phenomenon called Temperature Inversion. The cold air sinks in the valley and warmer air is present at higher elevations. When that happens (which is often), Sima is a haven to escape a cold day in town. I've seen days where it was -15 at the hill and -30 in town. In a nutshell: don't base your decisions on the weather in town.
If you have registered to patrol on a day where the hill is not opening because of cold weather, your attendance will still be counted towards the commitment.
PS: On a cold day, pay special attention to guests' clothing and signs of frostbite. Offer people to come to warm up in Top hut and keep some hot water on the wood stove. Blankets are available under the counter of Top Hut in case they are needed.