Japan - weather in January

January is the central month of winter in Japan, and is the coldest of the year. Since Japan is an archipelago very extended 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 daily average temperature is -5/-6 °C (21/23 °F) on the island of Hokkaido (see Abashiri, Sapporo), which is influenced by the Siberian currents, to the point that the north coast is reached by drifting icebergs.
On the island of Honshu, the average is -1 °C (30 °F) in the far north (see Aomori), 2/3 °C (35.5/37 °F) in the north, on both sides (see Niigata, Sendai), and 6/6.5 °C (43/43.5) on the southern coast (see Tokyo, Osaka). On the island of Kyushu, the average goes up to 9 °C (48 °F) on the south coast (see Kagoshima).
On the small southern islands, where the climate is almost tropical, the temperature is much higher, as the average is 17.5 °C (63.5 °F) in Okinawa and 19 °C (66 °F) in Ishigaki. On these islands, the cherry blossom (hanami) occurs earlier than on the main islands, and lasts longer, so much so that it occurs from mid-January to mid-February, with a peak around February 1st.
In Japan the sea attenuates extreme values, however, cold waves can occur in the north, during which the temperature can drop to -20 °C (-4 °F) on the island of Hokkaido, while in Tokyo and Osaka it drops only slightly below freezing.

Regarding precipitation, on average winter is the driest season in Japan, and January and February are the driest months, however, this is not true for the whole country. In fact, precipitation is frequent in the center-north, on the coasts facing north-west (see Sapporo, Aomori, Niigata, Kanazawa), where it often occurs in the form of snow, especially on the island of Hokkaido.
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 and in the north of the island of Honshu, but in the mountains, heavy snowfall also occurs further south, in the central part of Honshu, whose north-west side, east of Kanazawa, is called "snow country" or Yukiguni. In the mountains there are several ski lifts.

In January, the sea in Japan is warm enough for swimming only on the small southernmost islands, namely Okinawa and even more Miyakojima and Ishigaki, which are located just north of the Tropic of Cancer. However, air temperature is not very high and the sun does not shine often.

Japan is located at medium latitudes, however, in January the days are quite short, especially in the north, where the sun remains above the horizon for less than 10 hours per day.




See also: Japan, the weather in December - February
The climate of Japan