The recent bitter cold and heavy snows have been brought about by the La Nina weather pattern, which lowers the temperature of equatorial sea surface waters, the Meteorological Agency said.

The emergence of La Nina was also observed from December 2005 to February 2006, when around 150 people died as a result of heavy snow across Japan.

While the agency said the current cold air level is not as intense, it is warning of potentially unusual weather as the flow of cold air from China into Japan through early February causes heavy snow along the Sea of Japan coast.

Record snow accumulations for January have been recorded at three observation points in Hokkaido, including Shinshinotsu, where the level reached 213 cm as of Monday. In an average year, it sees around 68 cm of snow pile up.

In the city of Aomori, 391 cm of snow had accumulated as of Monday, around 1.7 times more than in an average year and the highest-ever January level.

Average temperatures between Jan. 1 and Jan. 17 were 1.1 degrees below normal in northern Japan, 0.9 degree in eastern Japan, 0.8 degree in western Japan and 0.2 degree in Okinawa.