New Delhi, Dec 31
With the mercury dipping down and the chilly cold waves hitting Delhites, the India Meteorological Department (IMD) on Thursday cited the western disturbance and global La Nina effect among the crucial factors behind the scene.

Speaking to ANI, Kuldeep Srivastava, Head, IMD's regional weather forecasting centre, New Delhi explained, "After December 12 western disturbances mostly affected the Western Himalayan region causing significant snowfall and rainfall over Jammu and Kashmir and Himachal Pradesh. The cold north-westerly winds further approach towards Delhi NCR from Jammu Kashmir and Himachal Pradesh."

"By the time, the fog over Punjab and Haryana further increases the coldness of winds moving towards Delhi. Also, the global La Nina effect plays its part in dipping the temperature," added Srivastava.

As per IMD, the number of cold spells observed over the national capital in 2020 is eight. IMD has recorded the mean minimum temperature (MMT) for December 2020 at 7.1 degrees Celsius.

The lowest MMT for December recorded since 1993 was 5.9 degrees Celsius in 1996. It was 6 degrees Celsius in 2005. The MMT for December was observed normal, that is, 8.3 degrees Celsius in 2018.