New Delhi | There is a 55 per cent chance of a weak La Nina affecting global weather and climate patterns over the next three months, the World Meteorological Organization (WMO) said on Thursday.

La Nina usually brings a temporary cooling effect on global average temperatures but many regions are still expected to record warmer-than-normal conditions, the UN climate and weather agency said in its latest update.

La Nina and El Nino are opposite phases of a Pacific Ocean climate cycle known as El Nino-Southern Oscillation (ENSO). La Nina is the periodic large-scale cooling of sea surface temperatures in the central and eastern equatorial Pacific Ocean and is linked to changes in tropical winds, pressure and rainfall.

El Nino is the "warm phase" of this cycle. It often weakens India's monsoon and increases the chances of drought.

According to the latest forecasts from WMO's Global Producing Centres for Seasonal Prediction, oceanic and atmospheric indicators in mid-November 2025 point to borderline La Nina conditions.

There is a 55 per cent probability of crossing the La Nina threshold during December-February 2025-26.

Earlier this week, the India Meteorological Department said normal to below-normal temperatures are expected in central India and the adjoining northwest and peninsular regions during the three-month winter season amid weak La Nina conditions.

WMO said that for January-March and February-April 2026, the chances of a return to ENSO-neutral conditions rise from about 65 per cent to 75 per cent. The likelihood of an El Nino is low.

While ENSO is a major driver of global climate patterns, it is not the only factor influencing Earth's climate.

WMO's Global Seasonal Climate Updates also account for other variability patterns, such as the North Atlantic Oscillation, Arctic Oscillation and Indian Ocean Dipole.