Japan Weather, climate and geography
Weather and climate
Best time to visit
Except for the Hokkaido area and the subtropical Okinawa region, the weather in Japan is mostly temperate, with four distinct seasons. Winters are cool and sunny in the south, cold and sunny around Tokyo (which occasionally has snow), and very cold around Hokkaido, which is covered in snow for up to four months a year. The Japan Sea coastline also often receives heavy snowfall during winter.
Summer, between June and September, ranges from warm to very hot with high levels of humidity in many areas. Typhoons, or tropical cyclones, with strong winds and torrential rains often hit Japan during August and September, but can occur through May to October. Strong typhoons often affect transport systems, causing rail and air services to be stopped, and there is a danger of landslides in rural areas.
Spring and autumn are generally mild throughout the country, and offer spectacular views of pretty sakura cherry blossoms and colourful autumnal leaves, respectively. Rain falls all over Japan throughout the year but June and early July is the main rainy season. Umbrellas are a daily essential during this season. Hokkaido, however, is generally much drier than the Tokyo area.
In Japan, lightweight cottons and linens are required throughout summer in most areas. To avoid sunstroke and sunburn it is advisable to wear a hat. According to the region, light to medium weight clothing is best during spring and autumn; whilst medium to heavy weight clothing is recommended for winter months. A light rain coat or jacket is useful during the rainy season in June and July. Much warmer clothes will be needed in the mountains all year round. Thermal innerwear is recommended if trekking, climbing or skiing. It's best to purchase all necessary clothing before arriving in Japan, as it can be difficult to find larger sizes.
The archipelago of Japan is separated from the Asian mainland by 160km (100 miles) of sea and split into four main islands: Honshu, Hokkaido, Kyushu and Shikoku. About 70% of the country is covered by hills and mountains, a number of which are active or dormant volcanoes, including Mount Fuji, Japan's highest peak, reaching 3,776m (12,388ft). Japan sits on major seismic fault lines and is susceptible to frequent earthquakes.
A series of mountain ranges runs from northern Hokkaido to southern Kyushu. The Japanese Alps (the most prominent range) run in a north-south direction through central Honshu. Lowlands and plains are small and scattered, mostly lying along the coast, and composed of alluvial lowlands and diluvial uplands.
The coastline is very long in relation to the land area, and has very varied features, for example, the deeply indented bays with good natural harbours tend to be adjacent to mountainous terrain. Many of Japan’s major cities are located on the coastline, and have extremely high population density.