Weather: Asia

To say that Asia is the world's largest, most populous continent doesn't quite do the place justice. The sheer scope of this land mass is hard to comprehend. Asia is almost twice the size of North America. You could cram five Australias – or 140 Italys – within its ample borders. On one side of Asia are the Indian Ocean and the tropical Pacific, which includes the world's warmest patch of open water. On the other side is the numbing year-round winter of the Arctic coast. In between, at the heart of Asia, is the fulcrum on which the whole continent's climate swings: the incomparably high and wide Tibetan plateau. It's almost as big as western and central Europe together, with an average elevation close to 5km/3 miles. The Tibetan plateau acts like a rock in the river of Asia's atmosphere, forcing gigantic volumes of air to move up or around it.

Large mountain systems tend to create a two-sided weather regime: wet on one side, dry on the other. But the geography of the Himalayan/Tibetan massif helps to create something entirely different: the Asian monsoon, in which the normal play of the seasons is exaggerated to cartoonish extremes. The monsoon is actually a set of neighbouring weather patterns that point in roughly the same directions. Together, they funnel relatively cool, dry air toward the southwest during the winter and moist, warm air  oward the northeast in the summer. The most famous monsoon, of course, belongs to India, where it virtually defines a way of life for hundreds of millions of people. China's monsoon, which also touches hundreds of millions, is no less vivid in its shaping of the seasons. Even the empty reaches of Siberia are affected by the intense seasonality of this atmospheric seesaw.

There's a plentiful variety of other weather elements at work across Asia. Deserts – from tropical to polar – are tucked in between mountain ranges or strewn across the heart of the continent. Asian temperature extremes can be mind-boggling. Parts of India can exceed 45°C/113°F during the tedious premonsoon days, and temperatures each winter plummet below –50°C/–58°F in Siberia. The warm waters of the western Pacific offer up the world's biggest crop of tropical cyclones (called typhoons in this region), many of which bring devastation to southern and eastern Asia.

In spite of all this meteorological drama, the Asian climate has its plus sides. The very reliability of the monsoon supports agriculture and settlement across a great sweep from India to Japan, where over two billion people live – more than 30 percent of the world's population. The monsoon also gives travellers a better-than-usual sense of what to expect at certain times of year. You needn't bother to bring an umbrella to Calcutta in December, but you'd be rash not to carry one in July.