Cold Wave Warning: IMD Predicts Temperature Dip Across Central, Northwest & Northeast India

India is heading for a sharper chill this winter, with the India Meteorological Department warning of more cold wave days than usual across parts of central, northwest and northeast India, as a strong polar vortex and ongoing La Niña conditions combine to pull temperatures down between December and February.

Spatial forecasts from the India Meteorological Department show that sections of Haryana, Rajasthan, Delhi and Gujarat are likely to experience below normal minimum temperatures, with one to four additional cold wave days in these areas during December to February, on top of the usual seasonal average for northwest India, which normally sees about five to six such days.

Cold wave forecast, polar vortex and La Niña link

Officials said the polar vortex, which has already affected conditions in November, is expected to keep temperatures largely below normal over northwest and central India through the next three months, while La Niña, which is linked to harsher winters in India, is also forecast to continue through the Northern Hemisphere winter period.

"Below normal temperatures and cold wave conditions over Madhya Pradesh had something to do with the polar vortex and the La Niña conditions. Now again the polar vortex has started impacting," said OP Sreejith, scientist and head, Climate Monitoring and Prediction Group, IMD.

"The forecast is based on a dynamical system. Not many western disturbances are expected over the winter period this time and La Niña will have an impact," added M Mohapatra, director general, IMD,.

Cold wave spread, temperature outlook and regional impact

According to the seasonal outlook, normal to below-normal night temperatures are projected over most of central India and neighbouring parts of peninsular and northwest India, while many other regions are expected to see above normal minimum temperatures, which means the coldest nights will be felt mainly across the central belt and adjoining northern states.

In December specifically, the India Meteorological Department expects normal to below-normal minimum temperatures over much of central and northwest India, along with the northern parts of peninsular India, even as daytime maximum temperatures are likely to stay above normal across most regions, except many pockets of central India and adjoining northwest and peninsular India where normal to slightly below normal day temperatures are predicted.

Cold wave conditions and rainfall pattern in December

The agency defines a cold wave when the minimum temperature drops below about 90 percent of the daily temperature readings for that location and falls under 15 degrees Celsius, with this pattern persisting for three consecutive days; only then is a cold wave event officially declared over a particular region.

Monthly rainfall over India as a whole during December is expected to remain within the normal range, which is defined as 79 to 121 percent of the long-period average, with above-normal rain likely over many parts of peninsular and west-central India and some parts of east-central and northeast India, while the remaining regions are forecast to see below normal rainfall.

Cold wave background, November trends and climate drivers

During November, most of India, except many parts of Northeast India and the peninsular region, experienced normal to below normal minimum temperatures, while rainfall was sharply deficient overall, particularly over northwest and central India and the South Peninsula, even as east and northeast India saw a modest rain surplus over the same month.

The India Meteorological Department said the polar vortex, whose modulation affected northwest and central India in November, is expected to keep exerting influence through winter, while the National Oceanic and Atmospheric Administration describes the polar vortex as a large zone of low pressure and cold air surrounding both poles, which is present year-round but weakens in summer and becomes stronger during winter.

La Niña, which the India Meteorological Department says is favoured to persist into the Northern Hemisphere winter with a 61 percent chance of shifting to ENSO-neutral between January and March 2026, refers to a periodic large-scale cooling of ocean surface waters in the central and eastern equatorial Pacific, along with changes in tropical wind, pressure and rainfall patterns, and typically brings impacts opposite to El Niño, especially across tropical regions, with La Niña usually tied to harsher winters in India.

Taken together, the polar vortex strengthening over the region, the ongoing La Niña phase and November’s widespread temperature dip and rainfall deficiency suggest that large parts of central and northwest India, along with some northeastern areas, are likely to face more frequent and stronger cold wave spells between December and February compared to the usual winter pattern.