Air and water temperatures, sunshine duration and rainfall vary extremly between different places on Lake Baikal.
Though the distance between Irkutsk and lake Baikal is only 70km (45miles) differences in temperature are quite significant. They are due to the huge water masses. During summer monthly temperatures are about 5-10°C (40-50°F) below Irkutsk temperatures at lake Baikal. In winter it is about 5-10°C (40-50°F) warmer than in the city.
In July the average temperature in Irkutsk is 25-30°C (75-85°F), while it drops to -25-30°C (-13-22°F) in January. Temperatures below -35°C (-30°F) for a longer period of time are not often found in Irkutsk, though experienced twice since 1999. At the river Lena north of Irkutsk temperatures can drop as low as -50°C (-60°F) and colder.
From mid January to late May lake Baikal is covered by a heavy ice shield. Due to the giant mass of water the lake freezes late in winter and melts late in spring. The ice is between 0.5 - 1.5m (1.6 - 5ft) thick.
During summer water temperatures stay below 10°C (50°F). Only in a few, shallowed areas they can rise up to 18°C (65°F). Well known for comfortably bathing season temperatures is Maloye More at the west coast of the lake, between the Olchon island and the coast.
October, November and December are those months with the highest amount of precipitation in the Baikal region. Summer months are very dry, also a characteristic of the continental climate.
With less than 200mm (8in) of precipitation per year, the west coast between Listvianka and Olchon is the driest area around Baikal. Relatively high amounts of precipitation can be found around the city Baikalsk (1,800mm/70in) and along the Chamar-Daban mountain ranges on both sides of the Northern Baikal (1,000mm/40in). New York City has an annual amount of precipitation of about 1,100mm (45in).
The lake Baikal region can definitely be called a sunny region. The annual sunshine exceeds 2,500 hours, which comes close to the sunshine state Florida with ist annually 3,000 hours.