Lake Baikal is a rift lake in Russia, located in southern Siberia, between Irkutsk Oblast to the northwest and the Buryat Republic to the southeast. At 620 km long, Lake Baikal has the largest surface area of any freshwater lake which is the deepest lake in the world at 1,742 m.
In Lake Baikal, the water temperature varies significantly depending on location, depth, and time of the year. During the winter and spring, the surface freezes for 4–5 months; from early January to May–June (latest in the north), the entire lake surface is covered in ice. Approach of spring lingers on Lake Baikal for 10 — 15 days in comparison with adjacent areas, but a fall time is often quite long. The maximum recorded air temperature is +34 degrees Celsius, and average temperature increases in recent years.
The region of the Lake has big total duration of sunshine. For example, sunshine of the Big Goloustnoye reaches till 2524 o'clock that it is more than in the Black Sea resorts. Days without the sun are 37 in a year, and there are 48 days without the sun on the island of Olkhon. Special lines of climate are caused by the Baikal winds which have own names — Barguzin, Sarma, Verhovik, Kultuk, etc.