I read somewhere (I wish I could find the links) that during the Soviet times, the fuel rations your city/area got were based on the temperature. Makes sense, but obviously this created a great incentive for the people recording the temperatures to fudge the numbers down so they would get more fuel.
If you look at the NOAA world temperature maps for the past 10-20 years, Siberia is always running very hot. One can only wonder how much of that heat is real vs how much is due to the fudging in the past.
A lot of what is happening with temps up there is this: Since the cold war the number of observation sites has decreased. Both the US and USSR needed a lot of weather stations in the middle of nowhere for their bombers. With the end of the cold war, the number of sites world wide have dropped by half. A lot of sites in the middle of nowhere are gone...and the sites that are left are around cities and the heat islands.