Weather: Russia (including European Russia), Armenia, Azerbaijan, Georgia
Although its reputation precedes it, Russia's climate is extreme only after a particular fashion. There's no sugar-coating the fact that Russian winters are extremely cold. Yet much of the country enjoys warm mid-summer days that average above 20°C/68°F, and there are even a few bona fide hot spells. Thunderstorms are seldom intense outside of the mountains and the southwestern steppes. Periods of rain and snow, even if lengthy, tend to be on the light side across much of the country. The only places that see more than 1000mm/39in of moisture in a typical year are parts of the Pacific coast and some mountain stations.
The fact that Russia straddles Europe and Asia has meteorological, as well as political, implications. European Russia, home to much of the country's populace, is close enough to the Atlantic for modified maritime air to sweep in regularly. East of the Urals, the sparsely settled Asian portion of Russia is dominated by a mammoth pool of cold air that settles in each autumn and stays until spring. It's the lower elevations that feel the cold most sharply; hillsides can average as much as 20°C/38°F warmer than valleys. Even so, virtually all of Siberia dips below –40°C/–40°F at least once in a typical winter, and many places get far colder. The west-to-east temperature contrast means that Muscovites seeking relative warmth are just as likely to find it toward the west as toward the south. No other country can match Russia's extensive winter snowpack: it's cold enough across most of the nation to sustain a coating of more than 30cm/12in that lasts throughout the winter. However, Russia and other high-latitude locations have seen noticeable warming in recent decades, a strong signal of global change. Especially in European Russia, the extreme cold typically observed a few times each winter seems to be less frequent and less intense. Much of this region made it to midwinter 2007 without a persistent snow cover, a virtually unprecedented feat.
Spring arrives dramatically here. It may take until April or even May for the snowpack to disappear, but once it does, the long high-altitude days take over and it warms up quickly. Except on the Arctic coast and in the far east, where even July days can be quite dreary, summer moisture tends to occur as rain showers. Surprisingly, most of Russia gets the bulk of its annual moisture as rain rather than snow. As congenial as they are, Russian summers don't last long. By September, the light is fading fast above the Arctic Circle, and the first snowfalls set the stage for the Siberian cold pool to rebuild.
It's easy to understand why the greatest cities of Russia lie on its western fringes. The climate here is more like a chilled-down version of central Europe's than the bitter beast that rules Siberia. The coast of the Barents Sea, though it's north of the Arctic Circle, is tempered by the warm Gulf Stream. Winters on the coast are peppered with snow showers and run a shade less cold than in Moscow, while summers tend to be dank and drizzly; spring brings the best shot at crisp, clear weather. The forested heart of European Russia, including St Petersburg and Moscow, gets rain or snow about every other day on average, with the frequency dropping slightly toward the south. Summer showers may be complemented by a thunderstorm every few days, especially toward the Ukraine. These rains usually pass more quickly than the winter snows, which are seldom heavy, but often persistent. When the summer rains fail, drought can be widespread and smoke from forest fires may hang above the region. In the steppes of the south, warm, dry winds known as sukhovei can parch crops. Temperatures in European Russia seldom descend to Siberian levels, but you'll be lucky to see a single day climb above 6°C/43°F between December and March. Spring and autumn are rather brief affairs here, with predictable timing. Frosts arrive in October, the snowpack is in place by late November, and the spring thaw kicks in during April.
The climate is a bit warmer and far more varied in and near the Caucasus Mountains, extending from the southern tip of Russia into Georgia and Azerbaijan. Screaming winds that sail through the Transcaucasus valley – typically reaching hurricane force at least once per year around K'ut'aisi – produce dramatic winter warm-ups, especially toward the western end. The Caucasus themselves are quite cool in the summer; in the winter, sunny days between snowstorms help make the mountains more appealing than the cloudy lowlands just to the north. Spring brings frequent rain and thunder to the western Caucasus and the plateau at the heart of Armenia. Drier, warmer weather then settles into the high country for the summer. The western Transcaucasus, sheltered from Siberian air, is almost sub-tropical. Average highs top 30°C/86°F in July, and winter readings below –10°C/14°F are rare. Rainfall along the moist Black Sea coast is sometimes heavy but can also vary sharply from month to month. At the eastern end of the Transcaucasus, the lower Kura Valley and the Baku region of Azerbaijan enjoy plenty of bright, crisp winter weather and dusty summer heat. The same applies to Armenia, although extremely cold winter air may pool for days within the basins that pockmark the plateau.
This is the world capital of continental climates. With the Arctic frozen most of the year, there's no large, open body of water nearby to keep temperatures in check. This works to Siberia's advantage in the summer, when the air can warm to shirtsleeve levels and beyond. The city of Yakutsk, which has sunk below –60°C/–76°F in winter, has been known to soar to 38°C/100°F in summer. Even near the Arctic coast, where clouds and chilly onshore winds are almost constant in summer, strong south winds can bring startling warmth. Yet frosts are possible across northern Siberia even in July. Most days are mild rather than hot, with showers becoming less frequent as the summer progresses. During autumn and spring, western Siberia sees wild gyrations in temperature as Atlantic and Siberian air masses twirl around low-pressure centres crossing the forested taiga. Temperatures are relentlessly brutal during mid-winter in the heart of the Asian cold pool, which is often centred roughly from Lake Baikal to Verhoyansk. Yet during the worst of it, the sky is clear and the air remarkably still. You may hear the sound of your breath freezing, or a faint rustle, produced by tiny particles of ice fog settling to earth, that locals call the “whisper of the stars”. Along the shores of Lake Baikal, temperatures are moderated from the usual Siberian range, with cooler summers but milder winters (amazingly, some warmth percolates up through the frozen lake surface).
Siberia may win out on pure cold, but the eastern fringes of Russia score extra points for sheer ruggedness of their climate. Hellacious winds, some exceeding hurricane force, can lash parts of the Pacific coast in winter – when they make for deadly wind chill – as well as in summer. Not only does the Siberian high deliver bitterly cold air through the winter, but summer is marked by dreary fogs and chill coming off the slow-to-warm Arctic and northwest Pacific (nowhere else on Earth does sea ice build so close to the equator as in the Sea of Okhotsk).
Spring, with its periods of cold, clear calm, provides the most tolerable weather. Conditions across the peninsula of Kamchatka vary greatly from east to west: the interior is the brightest and driest area, while blizzards rake the coasts. Far out on the peninsula's south tip, Petropavlovsk is one of Russia's snowiest cities. The southeast Russian mainland, which hugs the Sea of Japan, gets a monsoon-driven climate more akin to northeast China's. Vladivostok is actually colder than Moscow by winter, but distinctly humid during the heart of its mild, rainy summer.