When weather goes as low as -30--40 degrees, you should be aware that coldness can kill.
Keep yourself warm!
You don't have to worry inside the houses, they are warm but when you go outside use warm clothes. If asked me warm clothes and red cheeks makes people beautiful when temperature gets lower that -25 degrees.
If the warming system of you appartment fails for some reason or you are lost outside when it's cold, ask help immediately! And always take care of all of your friends!
Don't leave anyone outside alone when it's dark and freezing, especially when having a party in place you don't know.
We don't have much extreme natural disasters but there are two things that you should not mess: thunderstorms and coldness.
Thunderstorms are common at the end of the summer. Lightning itself are not dangerous if you avoid being close to trees but in last few years in addition to lightning storms have caused downburst of wind. Those downburst can cut down whole forest and take roofs of a house.
So avoid being outside while a thunderstorm and read also other warnings from: