The western Russian territory is crossed by a range of mighty rivers and is divided, from the hydrographic point of view, into several basins, the largest of which is the one that pays tribute to the Caspian Sea, especially through the Volga, the largest European river (along 3531 km). The latter originates from the Rialto del Valdaj, collects most of the waters of the entire plain between the central Russian Rialto and the Urals, respectively drained by the former above all by the Volga itself and its tributary Oka, the latter by the Kama, the maximum tributary of the Volga (1805 km long, 507,000 km² of basin) and from the upper reaches of the Ural(2428 km). Like all Russian rivers, the Volga has a very irregular regime and during the thaw (April-May) it increases its flow up to 50 times that of the lean period (December-January); also for this reason it was regulated by a series of gigantic basins (another, powerful, is on the Kama) used both for the production of electricity and to guarantee navigation, according to which the Volga was connected to the Don to form the famous system of the “five seas”. The major tributary of the Black Sea (more precisely it flows into its northern branch, the Azov Sea) is the Don (1870 km), which drains the eastern section of the central Russian Rialto. The rivers that turn to the North have less importance and development: the northern Dvina it is the main arctic river. The drainage towards the Glacial Sea is made difficult by the flatness of the territory and by the moraine deposits; the great lakes, such as Ladoga and Onega, the largest in Europe, are part of arduous river routes that are explained by the weakness of the watersheds. Conversely, the Siberian hydrography is generally formed by rivers heading towards the Arctic Ocean. The western lowland is drained by the Ob (5410 km with its main tributary, the Irtyš) and the Jenisej (4092 km), rivers with a vast basin and large flows that have a mature equilibrium profile, but which tend seasonally to flood into the flat surfaces of the great Siberian depression. River of mighty dimensions is also the Lena(4400 km), which drains the Baikal region and the eastern section of the Siberian Plateau. The last of the great rivers heading towards the Arctic coast is the Kolyma (2513 km), between the mountains of the same name and the Čerski. The only important tributary of the Pacific is the Amur (4416 km with its tributary Silka), which flows in the vast depression between the Sihote-Alin mountains and the reliefs of northern China.
According to findjobdescriptions, the harshness of winter is the salient feature of the climate of the Russian lowlands. The frost affects it almost entirely and to an extent that, in the northernmost part, is evidenced by the frozen soils ( merzlota ) that date back to the Pleistocene. The average annual temperatures are very low, but above all low are the winter values, given the great weight that continentality has in determining the thermal conditions. In Moscow, January averages are –10 ºC; in St. Petersburg, further north but with a continentality more attenuated, –7 ºC. On the coast of the Barents Sea, averages normally drop to –20 ºC. In summer, again due to continentality, maximum values can also be high, but the averages reach 17 ºC in Moscow, in July, and 16 ºC in Saint Petersburg; on the Arctic coasts there are values of just under 10 ºC. Only in the limited coastal stretches bordering the Black and Caspian Seas is there a mild subtropical climate, measured by January averages of 4 ºC and July averages of 25 ºC. The relative poverty of rainfall is also connected to continentality, which everywhere does not exceed 800 mm per year and, in Moscow, reaches 600 mm; they generally decrease towards E and SE. As the high pressures ease, in spring, the thaw season begins, the recurring great episode in Russian life, with mud – present everywhere – due to the rapid melting of snow and ice from the ground, with rivers in flood, with the first rainfall, which will be more intense in summer. In the S, subject to the subtropical or Mediterranean regime, however, the reverse occurs: that is, winter and autumn rainfall prevail, while summers are drought. Even more severe is the climate of the Siberian region. On the Siberian Plateau, in the areas of Verhojansk and that is, winter and autumn rainfall prevail, while summers are drought. Even more severe is the climate of the Siberian region. On the Siberian Plateau, in the areas of Verhojansk and that is, winter and autumn rainfall prevail, while summers are drought. Even more severe is the climate of the Siberian region. On the Siberian Plateau, in the areas of Verhojansk and Ojmjakon, is the “cold pole”, where the lowest temperatures in the globe are recorded (down to –70 ºC), excluding Antarctica, and where the January averages are –48 ºC. This is due not only to the latitude but also to the accentuated continentality; the averages of July in the same area reach 13 ºC and therefore there are annual temperature fluctuations of even over 80 ºC. In the Siberian Lowlands, given the lower altitude, temperatures are relatively less rigid and in Novosibirsk, on its southern edge, the January averages are –25 ºC. Particular values are found in the region around Lake Baikal, which with its enormous mass of water manages to create milder climatic conditions; but also Vladivostok, which is also located at the latitude of central Europe and moreover is located on the sea, has January averages below –10 ºC and July averages below 20 ºC. Precipitation, given the poverty of the humid air masses that reach these regions, is scarce, not exceeding 500 mm per year everywhere and even lowering to less than 250 mm in the northernmost belt. It is mostly snowfall: snow, in some areas, lasts for more than 250 days a year on the ground.