The national capital is likely to witness its longest cold spell in December after 1997 with the Meteorological Department predicting another cold day on Tuesday.
According to Kuldeep Srivastava, head of the India Meteorological Department's regional forecasting centre, a "cold day" is when the maximum temperature is at least 4.5 notches below the normal.
A "severe cold day" is when the maximum temperature is at least 6.5 degrees Celsius below the normal, he said. Since December 16, the national capital has witnessed eight consecutive cold days or an eight-day cold spell so far, he said, adding that it has already equalled the eight-day cold spell in December 2014.
Another cold day is predicted on Tuesday, Srivastava said. "Delhi had witnessed 17 cold days and a 13-day cold spell in December 1997," he said. The national capital may witness a cold wave on December 28 and 29 as the minimum temperature is likely to drop to 4 degrees Celsius, he said.