India Records Warmest October Since 1901, Monthly Mean Temperature 1.2℃ Above Normal – News18

Last Updated:November 02, 2024, 11:46 IST

Four of the top five warmest Octobers since 1901 occurred in the last decade: 2024, 2017, 2015, and 2020. The southern peninsula has shown a higher increase in day and night temperatures in recent times, compared to other parts of India

India witnessed its warmest October since 1901 with monthly mean temperatures nearly 1.2℃ above normal, according to the India Meteorological Department (IMD), adding to a string of record-breaking temperatures recorded in recent times.

The warm weather was especially evident during nights, when the mean minimum temperature was recorded to be 21.8℃ — highest for this month in the last 123 years. Normally, the average monthly temperature settles around 25.7℃ for October, but this year it was 26.9℃ — an increase of about 1.2℃. Almost the entire India saw higher-than-usual minimum temperatures.

“It was quite warm. The temperatures are still about 2-5℃ above normal over most parts of Northwest India from Himachal Pradesh to even Madhya Pradesh. The mercury will start falling slowly and return to normal after the second week, but a sharp fall in temperatures is quite unlikely,” said IMD chief Dr M Mohapatra on Friday.

The data shows that four of the top five warmest Octobers in India since 1901 have occurred in the recent decade: 2024, 2017, 2015, and 2020. The southern peninsula has shown a higher increase in day and night temperatures in recent times, compared to other parts of India.

WHAT LED TO SPIKE IN TEMPERATURES?

According to MeT, a major reason for a warm October this year was absence of a significant number of Western Disturbances (WDs) over Northwest India. These are extratropical storms which originate from the Mediterranean Sea, travel eastwards to impact the western Himalayas and bring rains over Northwest India, which also lead to fall in temperatures.

Since there was no intense WD activity, Northwest India ended up with a rainfall deficit of nearly 75 per cent, and higher temperatures.

“Another reason was the development of around four active low-pressure systems, one of which also intensified into a cyclonic storm. When such systems develop, we observe easterly winds, which are associated with higher than normal temperatures. For cooler temperatures, we need north-westerlies, which were weaker,” he elaborated.

The delayed retreat of the southwest monsoon also contributed to a warm weather as the monsoonal winds do not enable the temperatures to fall, according to meteorologists.

Heading into November, the IMD has forecasted above-normal maximum and minimum temperatures over many parts of India — especially during the first two weeks, except some parts of the southern peninsula. Northwest India may again see weak WD activity. The overall rainfall for October also ended up normal, against the MeT’s forecast of above-normal rains.

ONSET OF WINTER?

While the IMD does not declare the onset of winter over India, a gradual fall in temperatures signals the start of the season. According to the IMD chief, January and February are defined as the winter months, and December to some extent. “We expect a gradual fall in temperatures after the second week, but no sharp drop,” he added.

Meanwhile, the development of La Nina — a global ocean phenomenon associated with cooler seas-surface temperatures — has been further delayed. According to MeT, neutral ENSO conditions continue to prevail over the equatorial Pacific Ocean, and La Nina could set up towards the end of this year.

“It is still evolving. Though there is no one-to-one relation with weather in India, but La Nina is normally associated with below-normal temperatures over India, so we could expect its impact in January-February,” added Mohapatra.

Overall, the rainfall over India is forecasted to be normal. However, it is likely to be above-normal over the southern peninsula with an active northeast monsoon. Another low-pressure system is expected to develop in the first week of November.