The national capital on Saturday morning recorded the coldest temperature of the season with the mercury plummeting to 2.4°C. According to the weatherman Delhi is under a cold spell since December 14 and is expected to witness its second-coldest December since 1901. Dense fog reduced visibility in parts of Delhi, disrupting traffic movement and the Air Quality was in the very poor category at 360. People were seen taking refuge in various night shelters across the city, and lighting fires to keep the cold away.