MercoPress. South Atlantic News Agency

La Niña forecast to hit Uruguay's agriculture

A wildfire during 2023's drought is fought by a crop duster plane in Rocha eastern Uruguay. Photo: Sebastian Astorga Rostani

Weather forecasters announced a high probability that the La Niña climate phenomenon will affect Uruguay during the 2025-2026 season, bringing significant challenges to the agricultural sector.

La Niña is defined by the anomalous cooling of the surface waters in the equatorial Pacific Ocean. This shift in temperature alters global atmospheric circulation patterns, typically leading to higher-than-normal temperatures and scarce rainfall in the southern cone of South America, including Uruguay, during the austral summer.

The United States' National Oceanic and Atmospheric Administration (NOAA), a federal agency under the Department of Commerce, estimates a 54% probability of La Niña developing during the December 2025–February 2026 quarter, according to a report from the body's Climate Prediction Center. The phenomenon is expected to prolong existing dry conditions, with effects lasting until April 2026. Despite mounting signs, the NOAA requires four to six consecutive weeks of negative sea temperature anomalies to officially declare a La Niña episode.

The combination of above-average heat and below-average precipitation is projected to begin in the spring of 2025, intensifying through the summer. These conditions are anticipated to pose a significant risk to agriculture, exacerbating the persistent drought vulnerability Uruguay has experienced in recent years.

October began with increasing evidence that the La Niña phenomenon is forming in the Equatorial Pacific. Sea surface temperature anomalies in the central-eastern Pacific have remained at levels suggesting the onset of La Niña for the second consecutive week, according to Metsul.

The drought event during the 2020–2022 La Niña was one of the driest in the last 60 years for Argentina, causing a crop failure of nearly 30 million tons of soy, corn, and wheat. While the south faces drought, the north and northeast of Brazil tend to see an increase in precipitation and potential flooding.

The International Research Institute for Climate and Society (IRI) estimates a 60% probability of La Niña establishing itself during the October to December quarter.