El Niño: Why are houses often recommended to be painted white?

The National Institute of Hydrology, Meteorology and Environmental Studies (Ideam) issued a warning on July 9, 2026, alerting citizens, local authorities, productive sectors and disaster risk management entities about the ongoing consolidation of El Niño conditions in the tropical Pacific Ocean. This assessment was based on continuous monitoring conducted by Ideam and analyses from major international climate prediction centers, including the U.S. National Oceanic and Atmospheric Administration (NOAA). While a blackout is not the most likely scenario, the risk remains, according to Isagen. Vice President-elect José Manuel Restrepo expressed concern, stating there is a real risk of an electricity blackout. The Ideam noted that there is an 81% probability that the phenomenon will reach a “very strong” intensity during October through December 2026, potentially placing it among the strongest El Niño events since 1950. A report from the Climate Prediction Center (CPC) of NOAA confirms that the ocean-atmosphere system maintains characteristics consistent with a developing and strengthening El Niño event. This is supported by positive sea surface temperature anomalies in the central and eastern equatorial Pacific, high subsurface heat content, and increasingly aligned atmospheric responses to ocean warming. Dynamic and statistical climate prediction models agree that the phenomenon will persist throughout the second half of 2026, with probabilities exceeding 97% that conditions will remain until early 2027. Probabilistic scenarios indicate an 81% chance that sea surface temperature anomalies in the Niño 3.4 region will surpass the 2.0°C threshold, classifying the event as very strong from September 2026 through January 2027. Over the past several months, a significant acceleration in warming has been observed in the equatorial Pacific, reflected in sustained increases in both surface and subsurface thermal anomalies. This evolution has been accompanied by westerly wind anomalies at lower levels, negative Southern Oscillation Index values, and convective patterns characteristic of a strengthening El Niño event. These signs demonstrate an increasingly robust interaction between the ocean and the tropical atmosphere. The transition from neutral conditions to a fully developed El Niño scenario has been rapid since the beginning of the year. As a result, leading international climate monitoring agencies, including NOAA, the International Research Institute for Climate and Society (IRI), the World Meteorological Organization (WMO) and Ideam, maintain high confidence in the continuation and intensification of the event over the coming months. This situation requires constant monitoring of hydro-meteorological conditions in Colombia, along with strengthened preparedness and risk management actions by national and territorial authorities. A strong or very strong El Niño event can lead to significant changes in precipitation patterns, increased air temperatures, reduced water flows in certain regions, and a higher likelihood of vegetation fires across different parts of the country. Technical analyses by Ideam suggest that, should the predicted climate model trends continue, air temperatures could rise above normal climatic values.