The National Meteorological Center (NMC) on Sunday warned that smog would hit north China from Monday night and build up in the next three days.
The smog will be particularly heavy in areas along the Yellow River and the Huai River, according to the NMC.
People should take precautions to protect themselves during the smoggy period.
From Sunday night to Wednesday, snow and sleet would freeze Tibet Plateau, the NMC said.
Rain is expected to dampen southeastern China in the coming week.