ABSTRACT
Tobolsk district is situated in the northern part of Tyumen region, in subboreal forest zone, and occupies 17.222 km2. Summer time climate is formed under the infl uence of cyclones moving from the west. However, intrusion of arctic air causes cooling and frosts in the beginning and in the end of summer period. Anticyclones of the Central Asia enhance climate continentally during winter, which leads to relative severity of the period [7]. Territories of the region are characterized by severe cold winter and short frost-free period. Not only annual but daily sharp temperature fl uctuations are observed, especially during spring. Climate instability is related to unhampered intrusion of arctic air masses from the north and dry air masses from Kazakhstan.
