According to the state disaster management department, three people died in Kishanganj, two each in Purnea, Gaya and Muzaffarpur, and one in Patna.
Earlier, seven people died in Araria district, two in Sheikhpura and one each in Purnea and Darbhanga.
In view of the weather, Chief Minister Nitish Kumar has ordered the closure of schools until Thursday. Most of them were to reopen at the end of the winter holidays on Monday.
He also directed the disaster management department to arrange bonfires for the poor.
The dense fog has delayed flights. Several long distance trains are running late, officials said.
The meteorological department said Gaya district recorded a low of 6.6 degrees Celsius and Patna recorded a temperature of 8.8 degrees Celsius Tuesday.
Apart from the cold wave, some areas could see rainfall as well, a Met official, S.I. Lashkar, said. He added the temperatures would remain low for the next two days.
Published 05 January 2010, 06:53 IST