Heavy snow is falling in regions mainly along the Sea of Japan coast from western through eastern Japan, including the Noto Peninsula, which was struck by a powerful earthquake on New Year's Day.
The Japan Meteorological Agency says the weather is the result of the season's most powerful cold air mass combined with a winter-type pressure pattern.
Weather officials are warning of large-scale traffic disruptions after the snow suddenly intensified in the prefectures of Fukui and Shiga.
They forecast that the snow will continue into Thursday in areas affected by the quake in Ishikawa Prefecture's Noto Peninsula. Residents are being urged to stay alert for traffic problems and remain in safe locations.
In the 24 hours through Thursday morning, snowfall is expected to reach up to 90 centimeters in Niigata Prefecture, 80 centimeters in the Kinki region and 70 centimeters in the Hokuriku, Tohoku, Tokai and Chugoku regions.
The officials say significant snowfall could occur even in the flatlands of the Tokai, Kinki, Shikoku and Kyushu regions, which usually experience minimal snow.
Authorities in the Noto Peninsula are warning that buildings damaged by the quake could collapse under the weight of the snow.
Weather officials are also warning of severe cold. The daytime high for Wednesday is expected to be 1 degree Celsius in Toyama City, 2 degrees Celsius in Wajima City and 3 degrees Celsius in Kanazawa City.
The frequency of earthquakes in the affected areas has been decreasing, but seismic activity remains at high levels.
As of 4 a.m. on Wednesday, 1,506 tremors with an intensity of 1 or higher on the Japanese seismic scale of zero to seven had been observed.
Officials are urging residents to remain vigilant for quakes of upper 5 or stronger in the coming week.