Climate is a powerful force that connects oceans, land, and atmosphere. One of the most important global climate patterns is La Niña Effect, often called the “cool sister” of El Niño. Together, they form part of the El Niño–Southern Oscillation (ENSO) cycle, which regularly changes weather across the world. While El Niño is linked with unusually warm waters in the Pacific Ocean, La Niña is its opposite, marked by cooler sea surface temperatures in the central and eastern Pacific.
Though this change happens far away in the Pacific, its effects spread across continents, affecting rainfall, storms, agriculture, and even the economy.
What Causes La Niña?
La Niña occurs when strong trade winds push warm surface waters westward towards Asia and Australia. As a result, cold water rises from the deep ocean near South America in a process called upwelling. This leads to cooler sea surface temperatures in the eastern Pacific, which then influence wind patterns, clouds, and rainfall around the globe.
La Niña events usually appear every 2–7 years and may last from a few months to more than a year. The intensity can be weak, moderate, or strong, with stronger events causing more extreme impacts.
Global Consequences of La Niña
The effects of La Niña are not limited to the Pacific. They spread worldwide, creating very different conditions in different regions. Some of the key impacts include:
- Heavier Rainfall in Asia and Australia
Countries like India, Indonesia, and Australia often get more rainfall than usual, which can help agriculture but also increase the risk of floods and landslides. - Drought in the Americas
At the same time, parts of North and South America may face dry conditions, leading to water shortages and crop losses. - Stronger Hurricanes in the Atlantic
La Niña reduces a wind pattern called wind shear, which usually breaks up hurricanes. With weaker wind shear, hurricanes in the Atlantic can become more frequent and stronger. - Cold Winters in Some Regions
In North America and parts of Asia, La Niña winters are often colder than normal, with more snow and longer cold spells. - Agriculture and Economy The changes in rainfall and temperature affect crops around the world. Some regions may see bumper harvests, while others face droughts, floods, or frost damage. These changes often push up global food prices and hurt farmers’ income.
La Niña and India: Usual Patterns
India’s climate is closely tied to ENSO events. In La Niña years, India generally sees:
- Stronger monsoon rains – Good for kharif crops like rice and pulses.
- Colder winters in the north – Leading to cold waves and frost.
- Higher risk of cyclones in the Bay of Bengal – Especially during the post-monsoon season.
These impacts are not the same every time, but history shows a clear link between La Niña and India’s seasonal weather.
What About 2025?
Monsoon Season
The Indian Meteorological Department (IMD) has said that during the 2025 southwest monsoon, ENSO-neutral conditions are likely. This means that La Niña is not expected to strongly control the monsoon rainfall this year. Most regions are expected to get rainfall close to normal, though some may still face heavier showers due to local conditions.
Post-Monsoon Cyclones
Meteorologists warn that if La Niña builds up by the end of the year, cyclone chances in the Bay of Bengal may increase. States like Odisha, Andhra Pradesh, and West Bengal need to stay alert for stronger storms in October and November.
Winter 2025–26
The clearest impact of La Niña in India may come during the winter season. Forecasts suggest that northern India could see a harsher winter this year. Places like Delhi, Haryana, Punjab, and Uttar Pradesh may experience long cold waves, lower temperatures, and frost. In hilly areas, snowfall could be heavier than usual, affecting transport and agriculture.
For farmers, this could pose risks to rabi crops like wheat, mustard, and pulses, which are sensitive to extreme cold. The Indian Council of Agricultural Research (ICAR) is already studying how such conditions may affect crop health and yields.
Challenges Ahead
Even though forecasts show a possible return of La Niña later in 2025, its exact strength is uncertain. Climate change adds more complexity because global warming can sometimes intensify rainfall and heat, even during La Niña. Other climate drivers like the Indian Ocean Dipole also play a role, which makes predicting exact impacts difficult.
Looking Forward
La Niña is a powerful climate pattern that begins with cooler Pacific waters but has worldwide effects. It can bring floods in some regions, droughts in others, more hurricanes, and colder winters.
For India in 2025, La Niña may not strongly impact the monsoon but could bring a colder winter, stronger post-monsoon cyclones, and risks for rabi crops. Staying prepared—through early warnings, crop planning, and community awareness—will help reduce the negative effects while taking advantage of the possible benefits of good rainfall.
