What is La Niña weather and how does it affect winters in India? Your guide

The World Meteorological Organization (WMO) had previously predicted a 55 percent chance of La Niña breaking out this winter, and the India Meteorological Department (IMD) hinted at a harsh winter in northern India in an October statement. La Nina weather was then expected to occur in October-November.

But it hadn’t arrived yet. The IMD now expects a “higher probability” of La Niña developing around early next year.

What is La Niña and how does it affect the weather in India? Here’s everything you need to know:

What impact does La Niña have on India?

La Niña means “little girl” in Spanish. The India Meteorological Department (IMD) describes it as an “abnormal cooling of sea temperatures in the equatorial Pacific region.”

La Niña is “a climate phenomenon characterized by significantly cooler sea surface temperatures (SST) in the central and eastern Pacific,” according to a government press release.

It is the opposite of El Niño and can significantly influence the Indian monsoon. La Niña and El Nino are two climate patterns in the Pacific Ocean that can affect weather patterns around the world, including India.

El Niño can last up to 18 months and La Niña can last up to three years. “The last multi-year La Niña event began in September 2020 and lasted until early 2023 – the first ‘triple dip’ La Niña of the 21st century,” the World Meteorological Organization said.

Impact of La Niña on India

La Niña typically brings more rainfall, while El Niño results in dry periods during the monsoon season. Historically, La Niña winters are also colder than El Niño winters in the Indo-Gangetic Plain (IGP), which includes Delhi, CEEW reported.

Below average temperatures (colder) are generally observed during the winter season during La Nina years. The Director General of the IMD had said in 2020 that during La Niña years, the temperature in the northern parts of the country usually becomes relatively low. “In this situation, the winter could be relatively colder,” he had said.

Additionally, during a La Niña event, “normal to above-average rainfall occurs during the southwest monsoon season over India,” the center said in early December.

“Most parts of the country receive above normal rainfall during La Nina years, except for the extreme north of India and some areas of northeastern India where below normal rainfall is expected during La Nina years,” it said it in the government statement.

While excessive rainfall during La Nina can result in flooding, crop damage, and livestock losses, it can also benefit rain-fed agriculture and groundwater tables.

“Increased rainfall associated with La Niña may sometimes lead to lower temperatures in the Indian region, which could impact the growth and development of certain kharif crops,” the government said.

Weak La Niña conditions are less likely to produce traditional winter impacts.

When should La Niña conditions be expected?

The IMD said in a Dec. 26 news release that “the likelihood of La Niña conditions is increased through early next year.” It says that neutral El Nino-Southern Oscillation (ENSO) conditions are currently observed over the equatorial Pacific.

“The probabilistic forecast suggests a higher probability of La Niña conditions developing around the 2025 JF season and an increased probability of La Niña conditions occurring by early next year,” the IMD said. “JF” season is the winter season which lasts from January to February in India.

Meanwhile, the NWS Climate Prediction Center recently predicted that La Niña conditions are most likely to occur in November 2024 to January 2025 (59% probability).

Other factors affecting Indian climate

The IMD says other factors such as Indian Ocean sea surface temperatures (SSTs) also influence India’s climate. “Above average sea surface temperatures (SSTs) are currently observed across most of the Indian Ocean…” it added.