The India Meteorological Department (IMD) warned Monday that after record high temperatures in October and November, winter is expected to be mild with fewer cold wave days. November 2024 was the third warmest month for mean temperatures and the second warmest month for daytime temperatures in India since 1901. For northwest India, it was the warmest November since 1901 for mean temperatures and second warmest for day and night temperatures.
With record-breaking mean and nighttime temperatures, the nation saw its warmest October in 123 years. After similar records in July, August, and September, October saw the fourth consecutive month of nighttime temperatures that broke records since observations started in 1901. With the exception of south peninsular India, where below-normal temperatures are probable, the weather office has predicted above-normal temperatures for the majority of the country from December to February. The majority of northwest, central, east, and northeast India are predicted to have below-normal cold wave days.
“During the upcoming winter season (December 2024 to February 2025), above-normal minimum temperatures are likely over most parts of the country. Above-normal maximum temperatures are likely over most parts of the country except most areas over south peninsular India, where normal to below-normal maximum temperatures are likely,” IMD said.
A cold wave happens when the daily minimum temperature is less than 15 degrees Celsius and goes below the 10th percentile of the daily value. If these conditions continue for three days in a row, it is considered a cold wave event. It is sometimes computed as a minimum temperature of less than 10°C and a negative deviation of more than five degrees in the nighttime low (for plains).
“Normally we see 5-6 cold wave days during December to February over the cold wave region which includes northwest, central, east and northeast India. This time, we can expect 2-4 fewer cold wave days compared to average,” said M Mohapatra, director general, IMD.
With the exception of a few regions in central India, the weather office predicted that December’s minimum and maximum temperatures would be above average throughout the majority of the nation. November has been unusually dry, especially for India’s northwest. The country as a whole saw a 15% rainfall deficit from October 1 to December 1, with northwest India seeing a 77.2% deficit. In November, there was a 54.5% nationwide rain deficit and a 79.9% deficit in northwest India.
“There was no active western disturbance in November and there was only one cyclonic circulation or activity towards end of the month which is Fengal which impacted Tamil Nadu coast. So it has been very dry during past two months,” Mohapatra said.
Although monthly rainfall in northwest India is predicted to be above normal (more than 121% of the Long Period Average), the pattern of insufficient rain is anticipated to persist throughout December. Normal to below-normal rainfall is likely over most parts of north and northwest India, and many areas of east and northeast India.
IMD data shows that the warmest Novembers have been in recent years – 2016 being the warmest, followed by 2024, 2000, 2007 and 2018. “Our data indicates that the top 5 warmest years have been recent years. It is the same trend for various regions including northwest India,” Mohapatra said.
Global authorities continue to make inaccurate La Nina forecasts, he added. La Nina was predicted to appear between October and December with a 57% possibility and last until January and March of 2025, but it hasn’t happened yet.
In contrast to El Nino, which is marked by abnormally high temperatures, La Nina is characterised by abnormally cold ocean temperatures in the Equatorial Pacific. Both usually peak in January after developing in the spring and summer in the northern hemisphere. The Oceanic Nino Index needs to fall to at least -0.5°C or -0.3°C and remain there for a few months in order to qualify as La Nina, which hasn’t happened this year.
La Nina is linked to strong monsoons, above-normal rainfall, and cooler winters in India, whereas El Nino usually delivers harsher summers and weaker monsoons.
