During February 2025, below-average sea surface temperatures (SSTs) weakened in the central and east-central equatorial Pacific Ocean [Fig. 1]. All weekly Niño indices reflected this decline, with near-to-below average values lingering in the Niño-3.4 and Niño-4 regions [Fig. 2]. Significant coastal warming was evident near South America, with the latest Niño-1+2 value at 1.6°C. This warming, however, was shallow (in the upper 50m) and was associated with low-level westerly wind anomalies over the eastern Pacific. Below-average subsurface temperatures also weakened [Fig. 3], but negative anomalies persisted at depth in the eastern Pacific and extended down to 200m in the central Pacific [Fig. 4]. Tropical Pacific atmospheric anomalies continued to indicate La Niña conditions. Low-level wind anomalies remained easterly over the western and central Pacific, while upper-level wind anomalies were westerly over the east-central Pacific. Convection was suppressed around the Date Line and was enhanced near Indonesia [Fig. 5]. The traditional and equatorial Southern Oscillation indices were positive. Collectively, the coupled ocean-atmosphere system reflected weakening La Niña conditions and a trend toward ENSO-neutral.

The IRI and North American multi-model ensemble predicts a transition to ENSO-neutral in the coming season [Fig. 6]. The forecast team concurs and predicts ENSO-neutral, with chances greater than 50% through July-September 2025. As is typical for forecasts made in the spring, there is large forecast uncertainty at longer time horizons, with no outcome exceeding a 50% chance (chances of El Niño are the lowest). In summary, ENSO-neutral is favored to develop in the next month and persist through the Northern Hemisphere summer (62% chance in June-August 2025; [Fig. 7]).