Map from Google - Siberia

In the endless Asian Russian territory, the climate is characterized by cold winters: in fact here there are the coldest inhabited places in the world. Moreover, if we exclude the northernmost part, whose climate is Arctic and sub-Arctic, and partly the east coast which has a cold maritime climate, in most of the territory the summer is warm, and it can even get hot, due to the strong continentality.
In almost all of Siberia, the average temperature in January is lower than -10 °C, and goes down to -45 °C in inland eastern areas. The July average is around freezing in the northern islands and along the Arctic coast, while it goes up to 20 °C in the southernmost areas.
During winter, in most of the country the powerful Siberian Anticyclone dominates, except in the eastern seas where the clashes between continental and maritime air masses give rise to intense low pressure areas, associated with snowfalls. In the vast plains, in the West Siberian Plain but also in the valleys of the Central Siberian Plateau and of Yakutia, cold air stagnates to the soil, and the sky is often gray, with frequent light snowfall, while outbreaks from the Arctic may lead to raging blizzards.
Precipitation is scarce almost everywhere during the long winter months, because of the cold: snowfalls are frequent but light, and the snow can be carried away by the wind; almost everywhere summer is the rainiest season, due to the greater availability of heat, sot that afternoon thunderstorms may occur in inland areas, while the south-eastern areas are affected by the Asian monsoon, and therefore the summer is even more rainy. In most of Siberia, the yearly rainfall is between 150 and 500 millimetres. In the far east, the peninsula of Kamchatka is the wettest region of mainland Siberia, so that in some areas precipitation exceeds 1,000 mm per year, and can experience a lot of snow in winter.
Southwest of Kamchatka, the Kuril Islands are still rainier, since precipitation reaches 1,500 mm per year. Here winters are snowy and stormy, for the clash between frigid air masses coming from continental Siberia, and mild air masses which rise from the subtropical latitudes of the Pacific. Summers in the Kurils are very cool, because the sea holds the cold accumulated during the winter months, and quite rainy.

The Siberian Pole of Cold
The Siberian winter becomes colder from west to east, since the currents, at least at high altitudes, normally blow from the west, so they have an Atlantic origin, and gradually cool down: the coldest area is therefore the eastern Republic of Yakutia (or Sakha). The coldest city is Ojmjakon, in the upper Indigirka valley, at 740 metres above sea level, where the average in January is -46 °C, while that of July arrives to 13 °C, with a lowest record of -70 °C. Another very cold city is Verkhoyansk, further north but in the plains, in the Yana River Valley, whose coldest record is -70 °C as well, or according to other sources -68 °C; here the average goes from -46 °C in January to 17 °C in July. Since the highest recorded temperature in Verkhoyansk is 37 °C, the highest temperature range has exceeded 100 degrees Celsius! In the past decades, when the climate was colder, in this area of eastern Siberia, the average temperature in January was below -50 °C. This area is the "Pole of Cold" of the Northern Hemisphere, in fact it's colder than the North Pole, and it's surpassed only by the central area of Antarctica. At these temperatures a human being is likely to freeze in a few minutes, if not properly covered, while buildings tend to become brittle because of the cold.
Average temperatures - Ojmjakon
Min (°C)-51-48-41-25-6251-4-21-41-49
Max (°C)-42-36-22-571821188-10-32-40

Precipitation in Ojmjakon is scarce during the long winter, given the cold; no wonder the rainiest season is summer, when the rains are not still abundant. Here is average precipitation.
Average precipitation - Ojmjakon
Prec. (mm)6756133545402314128212

In Yakutsk, the capital of Yakutia, the average goes from -41 °C in January to 18.5 °C in July, while in the last century the average in January was -45 °C. Here, the lowest record is -64 °C, while the highest is 38 °C. In an average year, 240 mm of rain or snow fall, with a summer maximum of 40 mm in July, and a minimum in winter, of just 8/10 mm per month from December to March, of course not in the form of rain but of light snow.
Average temperatures - Yakutsk
Min (°C)-45-41-29-13081280-13-34-43
Max (°C)-37-30-1311322252112-4-25-35

Siberia, arctic and subarctic climate zone

Along the northern coast of the Arctic Ocean, the average in January and February ranges from -20 °C in the west, to less than -30 °C in the central and eastern part, and rises again to around -25 °C in the far east, and -20 °C in the Bering Strait, beyond which there is Alaska. In the arctic regions, the lowest records hover around -45/-47 °C, which means that they are not lower than those of the southern part of the Siberian mainland.
Here are the average temperatures of Tiksi, on the northern coast of the Sakha Republic (therefore, in the coldest part of the coast, the central-eastern one). The summer temperatures, low but above freezing, make it an example of subarctic climate.
Average temperatures - Tiksi
Min (°C)-36-34-31-24-10034-1-16-28-32
Max (°C)-29-27-22-14-3711104-9-21-25

The sea is frozen solid from November to May; remember that being salted, the sea freezes at about -2 ° C.
Sea temperature - Tiksi
Sea (°C)-2-2-2-2-202330-2-2

During summer, the temperatures remain around freezing in the northernmost islands (where the climate is arctic), they are around 3/4 °C along the northern coast, and up to 10 °C a few hundred kilometres to the south (limit of the subarctic climate). The highest recorded temperatures are around 15/20 °C in the Arctic islands, and around 25/27 °C along the northern coast of the continent. Precipitation is scarce in winter, when it occurs in the form of light snow, and it's more abundant in summer, when it can still occur in the form of snow along the coasts and especially the northern islands.
Here are the average temperatures of Zhokhov Island, located at a latitude of 76° N, belonging to the group of New Siberian Islands. Here the climate is arctic.
Average temperatures - Zhokhov Island
Zhokhov IslandJanFebMarAprMayJunJulAugSepOctNovDec
Min (°C)-32-32-31-24-12-3-1-2-7-2-26-30
Max (°C)-26-27-24-17-7031-3-11-20-24

Siberia, southern cities

In the southern plains, where there are the major cities, located along the Trans-Siberian Railway, the climate is strongly continental, but more forgiving than the northern areas, not so much for the lowest records, which are very low here as well, but for the warmer and longer summer.
For example, in Yekaterinburg, the former Sverdlovsk, near the Ural Mountains, the average temperature goes from -14.5 °C in January to 19 °C in July. In winter the temperature can drop below -40 °C, while in summer it can exceed 35 °C.
Average temperatures - Yekaterinburg
Min (°C)-18-16-8061114116-1-8-15
Max (°C)-11-811017222421145-3-8

In a typical year, 500 mm of rain or snow fall, with a summer maximum of 70 mm in July, and a minimum in winter, around 10 mm from December to March. Snowfall occurs from October to April. Here is the average precipitation.
Average precipitation - Yekaterinburg
Prec. (mm)252015304575806555403025500

Further east, in Omsk, the climate becomes more continental, so that the average temperature goes from -17.5 °C in January to 20 °C in July.
Average temperatures - Omsk
Min (°C)-22-21-13-151214116-2-11-19
Max (°C)-13-12-3918242622166-4-10

In Omsk, precipitation decreases to 390 mm per year, because the city is located in the arid zone of Central Asia, even though it maintains the same pattern, with a winter minimum and a summer maximum. Here is the average precipitation.
Average precipitation - Omsk
Prec. (mm)221414203555605535353022390

Further to the east, in Novosibirsk and Krasnoyarsk, the climate is similar to that of Omsk, but the rainfall increases slightly, again breaking 400 mm per year, because we enter the area which is affected by the Asian monsoon, with some more rains during summer.
Further to the east, in Irkutsk, near Lake Baikal, 500 metres above sea level, the average goes from -20 °C in January to 18 °C in July. The rainfall amounts to 410 mm per year; the cold record of the last thirty years is -50 °C.
In eastern Siberia, north of China, the effect of the summer monsoon is more noticeable, so that rainfall exceeds 100 mm in the month of July. In Blagoveshchensk, on the Amur River and near the border with China, the average is between -22.5 °C in January to 21.5 °C in July. The records of the last thirty years are: -45 °C the lowest, and 39 °C the highest.
Average temperatures - Blagoveshchensk
Min (°C)-28-24-13-261317147-2-15-25
Max (°C)-17-12-11019252725189-5-16

Here precipitation amounts to 575 mm per year, with a minimum from December to February, of less than 10 mm per month, and a maximum in July and August, of 125 mm per month. Here is the average precipitation.
Average precipitation - Blagoveshchensk
Prec. (mm)551235459013513070221410575

Siberia, eastern coasts and islands

In the long eastern coastline, the presence of the sea makes the climate more temperate, so that winter is less frigid, while summer is cold (or at least cool) and wet. In winter, cold currents carry drifting ice towards the island of Hokkaido in Japan. During summer, fogs are frequent in the central and northern areas; if we exclude the northernmost area, August is the warmer month, albeit slightly, because the sea warms up more slowly than the mainland.
South of the Bering Strait, the coast bordering the Bering Sea has a subarctic climate, with long, cold winters and very cool summers; the average in July and August is around 10 °C. In the northeast, in Anadyr, in the gulf of the same name, the average temperature goes from -22.5 °C in February to 11 °C in July; precipitation amounts to 270 mm per year, with the usual summer maximum. The city is located in a sheltered bay, but along the coast of the Bering Sea, the annual rainfall generally exceeds 500 mm.
Average temperatures - Anadyr
Min (°C)-23-26-24-18-62871-9-19-24
Max (°C)-15-19-17-1011014137-4-12-16

In this northern part of the Bering Sea, the sea remains frozen solid from January to March, while it is partially frozen in December, April and May.
Sea temperature - Anadyr
Sea (°C)-2-2-2-1-1289621-1

Further south, in Magadan, in the Sea of Okhotsk, the average is between -17 °C in January and 12 °C in August: winter is cold and dry, because this season is dominated by the currents from the mainland, which then pick up some moisture and bring snowfall over Kamchatka. The annual precipitation amounts to 550 mm, with a maximum of 85 mm in August. Snowfalls occur from October to May, but are not abundant because, as mentioned, the winter is dry.
Average temperatures - Magadan
Min (°C)-20-18-15-8-15995-4-14-17
Max (°C)-15-13-8-25111415101-9-13

In Petropavlovsk-Kamčatskij, in the wet peninsula of Kamčatka, the average goes from -8 °C in January to 12 °C in August.
Average temperatures - Petropavlovsk
Min (°C)-11-11-8-41591072-5-8
Max (°C)-6-5-3161114151270-4

Precipitation amounts to 1,300 mm, and is frequent throughout the year, which means that in winter there are heavy snowfalls. The rainiest season, however, is autumn. Here is the average precipitation.
Average precipitation - Petropavlovsk
Prec. (mm)110901751107560701051001451801151335

At Petropavlovsk, the sea remains cold even in summer, reaching 11 °C in August and September.
Sea temperature - Petropavlovsk
Sea (°C)211136101111853

The island of Sakhalin has a bit warmer summer, while winter is cold, with heavy snowfall. In summer, due to the effect of the Asian monsoon, precipitation is higher than 100 mm per month; this island can also be affected by occasional typhoons.
Average temperatures - Yuzhno Sakhalinsk
Yuzhno SakhalinskJanFebMarAprMayJunJulAugSepOctNovDec
Yuzhno SakhalinskJFMAMJJASOND
Min (°C)-17-17-11-238121492-513
Max (°C)-7-5071318212219123-4

In Vladivostok, on the coast of the Sea of Japan, in the southernmost part of Siberia, the average goes from -12.5 °C in January to 20 °C in August.
Average temperatures - Vladivostok
Min (°C)-16-14-616111517135-4-13
Max (°C)-9-6291517212319123-6

In Vladivostok here the summer rains are plentiful, so much so that in August 155 mm of rain fall, and although winter is dry and sunny, but also swept by dusty winds from Mongolia, the total annual precipitation amounts to 800 mm, thanks to the summer rains. Even this coastal area can occasionally be affected by typhoons in August and September, though with smaller effects compared with the southern areas from which they come. Typhoons are the tropical cyclones of south-eastern Asia. Here is the average precipitation.
Average precipitation - Vladivostok
Prec. (mm)1519255560100125155125654018800

Unlike in the rest of Siberia, at Vladivostok the sea warms up in summer, so that it becomes almost acceptable for swimming, especially in August.
Sea temperature - Vladivostok
Sea (°C)21248131821191494


When to go

The best time to visit the Asian part of Russia is summer, especially in July and August, being the warmest, while in the rest of the year the cold prevails.
In the arctic and subarctic regions, summer is the only period in which the temperature exceeds freezing, in particular in July and August, with a preference for July which is the warmest. It should be remembered in the northernmost regions, which have an Arctic climate, in summer the mud dominates, because the thaw never ends completely. On the contrary, in the remaining areas the thaw begins in April in the extreme south, and occurs progressively later as you move to the north, until June.
In the vast northern plains and in the area of the "Pole of Cold", the temperatures are acceptable from June to August, with a preference for the period mid-June to mid-August. Sometimes it can get hot during the day, but it can still get cold at night, sometimes even around freezing.
In the southern cities, the best period runs from June to August, even though the temperature is usually above freezing even in May and September.
In the eastern coastal regions, the best months are July and August, although they are quite foggy and rainy, because they are nonetheless the least cold. In the southernemost part, in Vladivostok the best period is from July to September, although it is the rainiest because of the summer monsoon.

What to pack

In winter: big chill clothing, synthetic thermal long underwear, fleece, parka, fur hat, wind jacket in Goretex, warm boots.

In summer: in Arctic coasts and islands: warm clothing, down jacket, hat, gloves, raincoat; in the continental areas and the southern cities, spring/autumn clothes, short-sleeved shirts for hot days, jacket and sweater for the evening, warmer in the northern areas; raincoat or umbrella especially in the eastern monsoon area (see Vladivostok). On the eastern coasts and islands, spring/autumn clothes, sweater, warm jacket, raincoat; gloves and hat for the northern part and offshore trips. In the mountains, warmer clothes depending on altitude; for the highest mountains, fleece, down jacket, warm hat, gloves, scarf.