Patna, the bone-chilling cold for the last four days has made the condition of people miserable. The cold westerly wind has increased the chill. According to the Meteorological Department, snowfall is happening in the hilly areas. Its effect has been felt in Bihar and the surrounding states. On Saturday morning, dense fog was seen in many districts including Patna, Purnia, Bhagalpur, Madhepura, Gopalganj, Buxar. The Meteorological Department has also issued a yellow alert in 23 areas. It has been said that there are chances of cold wave in these districts. Also, fog will remain for a long time.