The lowest temperature recorded in Harbin, Heilongjiang province, was -29 C on Sunday, not much colder than the highest of -22 C. Tuesday is predicted to be the coldest day, when the thermometer is expected to record -33 C.
In the neighboring province of Jilin, the lowest temperatures in the cities of Changchun, Liaoyuan, Tonghua and Baishan could also plunge to -33 C on Tuesday, the center said.
The average temperature in Jilin this winter has been -24 C, 11 to 14 degrees lower than in other years.
In Changchun, capital of Jilin province, the city government has asked that home heating be increased.
Homeless aid stations in the city also responded by searching for those in need of help, especially children.
In Shenyang, capital of Liaoning province, residents said even their eyelashes began to ice up when they went outside.
"The wind blowing on your face is like knives," said Zhao Jie, a resident. "Nobody is willing to stay outdoors after work.
"Many old residential buildings have problems with their heating, so the temperature in these places may be quite low."