Temperatures shot up to summer levels Saturday as warm air moving in from the south set record highs in more than 105 places throughout Japan, prompting the Meteorological Agency to issue an avalanche warning.
The agency said the unseasonal heat wave could cause avalanches and mudslides in snowy regions, and that violent winds and tidal waves would pose a danger in northern areas through Sunday.
The heat shocked many on the Pacific coast, where Shizuoka hit 26.8 and Odawara, Kanagawa Prefecture, hit 26.1 in the afternoon, making their winters feel like early July.
Tokyo logged 23.9, its highest this year, just after 2 p.m.
The sudden surge in temperatures is already being blamed for cracking a frozen lake in Ishikawa, Fukushima Prefecture, where two people fishing went missing.
Meanwhile, in Yurihonjo, Akita Prefecture, a mountain stream flooded four houses as meltwater and heavy rain caused it to overflow.
Itoigawa in Niigata Prefecture logged a record high for February of 23.6 as early as 1:40 a.m., the agency said.
On the northern Pacific coast, strong winds forced the suspension of train runs in many areas.
Erimo Cape in Hokkaido was hit by 128 kph winds at around 2 p.m., while Nikko, Tochigi Prefecture, recorded 121 kph gusts at around 11:30 a.m.