The winters could be cooler in the plains due to the prevailing La Nina conditions though it does not have a direct relationship and also due to influence of the polar vortex.
Polar vortex is a long low pressure system located near the North or South Pole, especially during the winters.
La Niña refers to the large-scale cooling of ocean surface temperatures in the central and eastern equatorial Pacific Ocean, coupled with changes in tropical atmospheric circulation such as winds, pressure and rainfall.
It is generally associated with intense and prolonged rains in the monsoon season in India and colder-than-usual winters, particularly in northern regions.
The IMD is also expecting four to five "extra" days of cold wave conditions in Rajasthan, Uttar Pradesh, Madhya Pradesh, Haryana, Punjab and some parts of Maharashtra in December-February.
“These areas normally experience four to six days of cold wave conditions during the December-February period but this year it could be up to 10 days of cold waves,” IMD director general Mrutyunjay Mohapatra told reporters.
“During the upcoming winter season (December 2025 to February 2026), normal-to-below-normal minimum temperatures are likely over most parts of central India and adjoining peninsular and northwest India. Above-normal minimum temperatures are likely over the remaining parts of the country,” he said.
During the season, maximum temperatures are expected to be normal-to-below-normal across most parts of the country, he added.
The season's first spell of cold-to-severe-cold wave conditions started early and was observed only in isolated pockets over west, central and adjoining east India. It was mainly in northeast Rajasthan, south Haryana, north Madhya Pradesh, south Uttar Pradesh and north Chhattisgarh, between November 8 and 18 and over north interior Maharashtra on November 15-20.
Another cold wave spell is expected in parts of northwest and central India around December 3-5, the IMD chief said.
In December, the IMD chief said normal-to-below-normal monthly minimum temperatures are likely over most parts of central and northwest India and northern parts of peninsular India. Above normal minimum temperatures are likely over the remaining parts of the country.
“The maximum temperatures during December 2025 are likely to be above normal over most parts of the country except many areas of central India and adjoining northwest and peninsular India, where normal-to-below-normal maximum temperatures are likely,” Mohapatra said.
 "Winter,cold wave")