Climate and Geographical Position
Khanty-Mansiysk Autonomous Okrug is located in the central part of the West-Siberian plain, one of the largest plains in the world. Two greatest rivers of Russia - the Ob and Irtysh, flow on the territory of the Okrug from the south to the north. Besides, the most significant rivers of the Okrug are the tributaries of the Ob: Vakh, Agan, Tromegan, Bolshoy Yugan, Lyamin, Pim, Bolshoy Salym, Nazym, Severnaya Sosva, Kazym; inflows of the Irtysh: the Konda and Sogom rivers. In winter rivers are covered with ice for a long period - 6 months and less. The Okrug is located within the limits of one natural zone - forest zone. The basic part of the Okrug territory is occupied by swamped taiga. Among swamps and forests there are more than 25 ths. lakes. They are filled mainly with winter and partially summer precipitations. Ugra territory suffers from simultaneous influence of the ocean and continent, it is the main factor of climate formation. Security of the territory by Urals mountains influences greatly in the West. Absence of security in the North allows cold Arctic air to reach the continent during the whole year. At the same time openness in the South brings warmed-up continental air of midlatitudes. Okrug climate is sharply continental: severe winter with strong winds and snowstorms, spring cold weather, late spring and early frosts. But for all that, owing to much sun and warm, summer is mainly warm but short. Weather, observed in the Okrug, is very changeable, winds are often observed. Summer decreasing of wind's speed is a characteristic feature of all territory, especially in the areas, adjoining the Urals (Nyaksimvol, Saranpaul, Sosva) - so called wind "shadow". Squally winds can be intensified even with average speed sometimes. For example, on July, 6, 1983, it was observed a squall with intensification (till 33 m/s), the average wind speed in July - 3 m/s. Territory of the Khanty-Mansiysk Autonomous Okrug - Ugra, as compared to the European territory of Russia, is remarkable for low temperatures and strong severe climate, including in summer. Cold weather in summer is caused by the fact that Western Siberia is located at this time mainly in the western periphery zone of summer Asian depression in which northern winds bringing cold Arctic air, prevail. Spring is the shortest and dry season in the year with prevailing of fair and windy weather. There is snow on the most part of the Okrug in April. Last frosts are observed in the end of May - beginning of June. Average duration of frost-free period comprises from 65 days (in the northern areas of the Okrug) to 115 days (in the southern areas of the Okrug). Summer is rather hot, but short, the average temperature in July is +16º+19º. Absolute upper limit of atmospheric air on the Okrug territory is +34º-37º. Passing to autumn is noted by significant lowering of temperature. At the end of August the first frosts are observed in the northern areas, in the middle of September - on the rest Okrug territory. Winter period with stable snow cover and frosts lasts 5-6 months. Thaw days number is not large on the average. January and February are remarkable for fair and freezing weather with strong radiation cooling and gentle breezes. Absolute lower limit of atmospheric air on the Okrug territory varies from -48º to -60º. (Information (air temperature) from Scientific Reference Book on Climate, Series 3, Parts 1-6, Issue 17, is used). The average annual precipitations over the Okrug are 443-610 mm (based on long-term data, calculated for the period of 1961-1990). Maximum precipitations are observed in July and August. At this time precipitations are mainly storm, daily maximum can reach 20-25 mm. There were days when upper daily limit of precipitations exceeded 50 and even 100 mm, Fro instance, on July, 1996 in the town of Nizhnevartovsk it was observed maximum level of daily precipitations - 162 mm. |
