Japan
is a temperate region with, more or less, four seasons (some believe the
rainy season should be a fifth season), but because of its great length
from north to south, its climate varies from region to region: the far
north is very cold in the winter, while the far south is subtropical. The
climate is also affected by the seasonal winds blown from the continent
to the ocean in winters and vice versa in summers. The waters of the Kuroshio
Current also warm the Pacific side of Japan, sustaining the coral reefs
of Japan, the northernmost coral reefs in the world. Unfortunately, due
to pollution, these reefs are now dying.
Late June and early July are a rainy season (except in Hokkaido), as a
seasonal rain front or baiu zensen (????) stays above Japan. In the late
summer and early autumn, typhoons develop from tropical depressions generated
near the equator, and track from the southwest to the northeast, often
bringing heavy rain.
Japan's varied geographical features divide it into six principal climatic
zones.
Hokkaido: Hokkaido has a temperate climate with long, cold winters and
cool summers. Precipitation is not heavy, but the islands usually develop
deep snow banks in the winter.
Sea of Japan: The northwest wind in the wintertime brings heavy snowfall.
In summers, the region is cooler than the Pacific area, but it sometimes
experiences extremely hot temperatures due to the Foehn wind phenomenon.
Central Highlands (Chuo-kochi): A typical inland climate, with large temperature
differences between summers and winters and between days and nights. Precipitation
is light.
Seto Inland Sea (Seto-naikai): The Mountains of the Chugoku and Shikoku
regions block the seasonal winds, bringing mild weather throughout the
year.
Pacific Ocean: Experiences cold winters with little snowfall and hot, humid
summers due to the southeast seasonal wind.
Nansei-shoto (Ryukyu) or Southwest Islands: Has a subtropical climate with
warm winters and hot summers. Precipitation is very heavy, especially during
the rainy season. Typhoons are common; in 2004 a record number of 10 typhoons
reached the main islands.