Japan - weather in December

December is the first winter month in Japan. Since it is a very extended archipelago in latitude, the climate varies greatly, as it is very cold and snowy in the north, quite mild in the center-south, and very mild on the small southern islands.

In fact, the average temperature is -2/-3 °C (27/28 °F) on the island of Hokkaido (see Abashiri, Sapporo), which is influenced by Siberian currents.
On the island of Honshu, the average is 1.5 °C (34.5 °F) in the far north (see Aomori), 4.5/5.5 °C (40/42 °F) in the north, on both sides (see Niigata, Sendai), and 8.5/9 °C (47/48 °F) on the southern coast (see Tokyo, Osaka). On the island of Kyushu, the average reaches up to 11.5 °C (52.5 °F) on the south coast (see Kagoshima).
On the small southern islands, where the climate is almost tropical, the temperature is much higher, and the average is 19 °C (66 °F) in Okinawa and 20.5 °C (69 °F) in Ishigaki.
In Japan the sea attenuates extreme values, however, cold waves can occur in the north, during which the temperature can drop to -15 °C (5 °F) on the island of Hokkaido, while in Tokyo and Osaka drops to around freezing.

Regarding precipitation, on average winter is the driest season in Japan, however, this is not true for the entire country. In fact, precipitation is frequent in the center-north, on the coasts facing north-west (see Sapporo, Aomori, Niigata, Kanazawa), and is produced in the form of snow on the island of Hokkaido and in the mountains.
The rains are also quite abundant on the small southern islands (see Okinawa), while they are rarer on the coast facing east (see Sendai) and south-east (see Osaka, Tokyo), which is also the sunniest area.
At sea level, snowfall is abundant in the north, on the island of Hokkaido, but in the mountains, heavy snowfall occurs even further south, in the central part of Honshu, whose north-west side, to the east, Kanazawa is called the "land of snow" or Yukiguni. In the mountains there are several ski lifts.

In December, the sea in Japan is warm enough for swimming on the small southern islands (see Okinawa, Miyakojima and Ishigaki). However, rainfall is abundant, especially on the small southern islands, and the sun does not shine often.

Japan is located at medium latitudes, however, in December the days are quite short, especially in the north, where the sun remains above the horizon for about 9 hours a day. In the Northern Hemisphere, December is the month when the days are shortest, and December 21st is the winter solstice.




See also: Japan, the weather in November - January
The climate of Japan