As the Diwali festivities draw to a close, the much-awaited winter chill remains elusive in Delhi-NCR despite a slight drop in temperature in recent days, which has triggered a worrying rise in air pollution.

India experienced its warmest October since 1901, with the average temperature 1.23 degrees Celsius above normal. November will remain warm with no indication of winter ahead, the India Meteorological Department (IMD) said.

The average temperature in October was recorded at 26.92 degrees Celsius, the warmest since 1901, against the normal of 25.69 degrees Celsius, IMD Director General Mrityunjay Mohapatra said on November 1. for the country as a whole.

Winter in Delhi usually starts in late November or early December and ends in the first week of March.

Mohapatra attributed the warmer weather to the absence of western disturbances and inflow of easterly winds due to active low pressure systems in the Bay of Bengal.

“In northwest India, northwesterly winds are required for cooler temperatures. Monsoon flow was also there which does not allow the temperature to drop,” he said.

According to the forecast, temperatures will continue to remain 2-5 degrees above normal in the northwestern plains for at least the next two weeks, before gradually decreasing.

The Met Office does not count November as a winter month and only considers January and February as winter months, while cold weather indices are available in December.

The delay in the onset of cold weather conditions is also likely due to the continued prevalence of neutral El Nino conditions in the equatorial Pacific Ocean.

The Met Office said the probability forecast indicates a higher chance of La Nina conditions developing between November and December in a gradual manner.

“The ENSO (El Nino – Southern Oscillation) conditions are slowly turning to the negative side and La Nina may set in by December,” Mohapatra said, adding that weather agencies around the world have got El Nino forecasts wrong this year.

During the winter months, La Nina causes a very cold, wave-like jet stream to flow through Afghanistan, Iran, and the Hindu Kush mountains. These strong and cold winds affect the degree of cold in India.

La Niña, a climate phenomenon associated with cooling ocean surface temperatures in the central and eastern equatorial Pacific, often brings good monsoon rains to the Indian subcontinent. However, despite predictions from global models, La Niña has been absent during the southwest monsoon months this year.

Earlier, the IMD had suggested the possibility of severe winter over north India, especially over the northwest and central regions, including Delhi-NCR. This forecast is related to the potential development of La Niña conditions in October and November.

During La Niña years, the colder-than-normal temperature phenomenon is usually observed in northern India, especially in the northwest and adjacent central regions, leading to possible cold snaps during winter.

Meanwhile, in the southern peninsula, the northeast monsoon is expected to bring above normal rainfall in November to Tamil Nadu, Puducherry and Karaikal, coastal Andhra Pradesh and Yanam, Rayalaseema, Kerala and Mahe and south interior Karnataka.

“Above normal to normal rainfall is likely over most parts of the country except northwest India and some areas of central India,” the IMD said.