>>> where at -15 can blow a rather strong wind.
>>> In more northern areas up to -20 for frost does not count.

Reminded, a friend told an army story, quite like the truth.
They were flying in the winter to Chelyabinsk or Ufa, I don’t remember exactly, a man twenty, half Siberians, half local Urals. At the airport they had to move onto another ship and fly on.
Before landing, the pilots learned the weather at the landing site. The same -15 and wind 5 meters per second. The Urals used to cheer for warm things, the Siberians, looking at them, began to tell something about the tropical paradise and palm trees.
Ten minutes after landing and landing, the Urals quietly stood waiting for the loading, while the Siberians with the screams of "how you live here at all" drove around the airport in search of warm drinks.