Dfd Climate Analysis
By: Hammad Chaudhry
The first two letters, Df, classify an area as having a cold continental climate without dry season. The third letter, d, indicates a very cold year in which the average temperature of the coldest month can reach less than -38°C (-36.4°F).
As you could see on this map, Dfd climates cover a big part of Siberia (a territory in Russia).