A cold air mass gripped much of the country on Saturday, with many regions experiencing their lowest temperatures this winter and heavy snow hitting Sea of Japan coastal areas.

One man died Saturday in Nagano Prefecture, apparently by a tree that snapped under the weight of snow, while at least 40 people were injured in other weather-related accidents, according a Kyodo News tally.

The Meteorological Agency issued warnings on snowstorms, especially in Sea of Japan coastal areas, through Monday. It also expects snow to settle in plains along the Pacific through Sunday as an even stronger cold air mass covers the archipelago.

The season's first snow was observed in Wakayama Prefecture as well as in Saga and Oita prefectures. Snow was also recorded in Nagoya and Hiroshima.

All Nippon Airways Co. and Japan Airlines Co. cancelled over 50 flights to or from areas on the Sea of Japan coast. Some services on the Tokaido, Sanyo and Hokkaido shinkansen lines saw delays.

The agency has asked people in affected areas to stay home and be careful in removing snow.

Over a 24-hour period through Saturday morning, up to 70 centimeters of snow had fallen in Niigata, 52 cm in Nagano Prefecture and 46 cm in Toyama Prefecture. The mercury plunged to minus 29.7 degrees Celsius (minus 21.5 Fahrenheit) in the Hokkaido village of Shimukappu, minus 14.9 in Kazuno in Akita Prefecture and minus 0.5 in downtown Tokyo.

Up to 100 cm of snow is forecast to fall in the Hokuriku region through Sunday morning, 70 cm in Kanto-Koshin and Tokai, 60 cm in Kinki and Chugoku, 50 cm in Tohoku and 40 cm in Hokkaido.

The cold weather struck as the annual unified college entrance examinations began, prompting concern over transportation delays. The number of applicants increased by 12,199 from last year to 575,967, including 471,842 high school students.