In its monthly discussion of April 2025, NOAA declared the El Niño episode of 2024-25 dead and instated La Niña watch, indicating that the models gave La Niña a greater possibility of formation during the summer of 2025. At the end of May Of 2025, the Pacific Ocean was already in an advanced stage of cooling, with SST anomalies reaching -0.9 ° C. In August 2025, NOAA and BoM have already stated that La Niña conditions were present. During the months of June and July 2025, large polar masses settled in South America, causing historical temperature records in countries such as Brazil and Argentina. In December 2025, the anomaly fell to a shocking -3.5 ° C, making La Niña 2025-26 the strongest ever recorded, causing great upheaval worldwide, since the climatic effects caused by the cooling were felt in several Sectors. The rains of the first semester of 2026 were the largest in the 21st century in the north and northeast of Brazil and the drought in the southern United States was one of the most intense. In February 2026, the Pacific Ocean temperatures began to rise, but even then, there was not enough warm-up to declare the end of this episode of La Niña. During the spring of 2026, the anomalies reached -1.4 ° C, but as of June, Niño 3.4 began to cool again. In July, NOAA warned of continued cooling of the Pacific during the fall of 2026 and that such cooling could reach the same levels as 2025. In December 2026, another La Niña peak was recorded, this time reaching anomaly of -3.0ºC . The effects of the peak of 2026-27 were as intense as those recorded in the 2025-26 season. Such events have entered into the climactic and scientific history, since that was the most intense ENSO episode recorded so far in the 21st century, defeating by far the El Niño of 2015-16. In February 2027, the ocean again warmed, but again, it was not enough to declare that episode of La Niña dead. After reaching a minimum anomaly of -1.0 ° C in May, the Pacific again cooled during the second half of 2027, but not as much as in 2025 and 2026. This third consecutive peak of La Niña reached a maximum anomaly of -2.2 ° C, or Is much weaker than in the previous two years, but still very strong. The effects provoked were very similar, but more attenuated. From January 2028, the Pacific Ocean warmed up and in March, NOAA reported that this episode of La Niña would finally come to an end in the spring of 2028. In May 2028, the La Niña episode of 2025 was declared dead -28. This La Niña has been uninterrupted for three years and has entered history as the strongest ever recorded.

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