The hard-core seasonality of Chinese climate gets moderated on its way to the Japanese archipelago. This chain of over 4000 islands runs from the tropics to the northern mid-latitudes, so there is plenty of north-to-south contrast. However, the broad strokes are similar to China's: wintertime cold and sweaty summer heat are interspersed with distinctly rainy transitions. Although the seasons here are as sharply defined as anywhere else, Japan's maritime location and its rugged topography provide a stimulating array of micro-climates and day-to-day weather change.
In winter, as the cold northwest winds of the Asian monsoon pick up moisture across the Sea of Japan, they lead to one of the world's great climate contrasts on either side of the mountains that bifurcate Honshu. The western sides of the main Japanese islands, especially central Honshu, are covered with heavy snow that falls almost daily in the heart of winter. Mount Ibuki holds the world record for snow depth – it reached a height of 1182cm/465in at one point in 1927 – and the lowlands often pile up more than 140cm/55in during the course of a winter, though the amounts vary markedly from year to year. Even the south end of Kyushu – near the latitude of Houston and Cairo – averages a few days of snow each winter. Japan's Pacific coast and the region around the Seto Naikai (Inland Sea) get the flip side of winter climate. Here, the squeezed-out monsoon winds deliver bright, chilly weather, with more hours of sunshine than some parts of summer see. From late winter into early spring, a few disturbances sweep up from Taiwan, bringing cold rain or snow to the southern and eastern cities.
Fitful spells of warm weather in March herald the spectacular northward march of cherry blossoms across Honshu in April. Mid-spring is usually a gorgeous time across Japan, with the exception of Mongolian dust storms (which yellow the sky several times each year), rare bouts of steady rain and the occasional hail-bearing thunderstorm. People lie low during the oppressive Bei-u rains, caused by the eastward extension of China's Mei-yu front. Almost everywhere, with the exception of Hokkaido, the thick overcast and heavy downpours last for several weeks, typically from mid-June to early July. Then, as if a switch is flipped, true summer kicks in. Both temperature and humidity soar to tropical levels and stay there into September. Sea breezes and afternoon thunderstorms (seldom intense) provide some relief from the oppressiveness. It's the best time for mountain climbing and other high-altitude diversions, as the conditions at elevation are still warm but less humid than at lower altitudes. A weaker version of the Bei-u front drifts southward from late September into October, bringing another few weeks of rain. These downpours are usually less intense and frequent than in the spring. Three or four typhoons typically strike Japan each autumn, with the southern coastlines most vulnerable to damage and flooding. From late October into November, foliage watchers savour the rich blue skies and cool-to-mild temperatures that prevail.
The northernmost of Japan's major islands, Hokkaido is several degrees cooler than most of the country year round. Though Hokkaido is a bit drier than Honshu overall, it still gets plentiful rain and snow, with annual precipitation exceeding 800mm/32in across the east and reaching 2000mm/79in in the west. Frequent fogs cling to the southeast coast from June into August. The intensity of winter's cold and summer's heat can vary noticeably from year to year across Hokkaido. At the other end of the archipelago, Japan's sub-tropical islands stay fairly dry in winter, although the weather can turn surprisingly chilly and overcast even as far southwest as Okinawa. Summer is hot, humid and sunny, punctuated with typhoons that may strike these isolated islands at full ferocity. Japan was pummelled by ten typhoons in 2005, beating the old record of six set in 1995. The deadliest of the barrage, Typhoon Tokage, killed 79 people.