During June 2025, ENSO-neutral continued, with near-average sea surface temperatures (SSTs) prevailing across most of the equatorial Pacific Ocean [Fig. 1]. The latest weekly Niño SST index values ranged from 0.0°C to +0.4°C [Fig. 2]. Subsurface temperature anomalies were weakly positive and nearly unchanged from last month [Fig. 3], with mostly above-average temperatures established along the thermocline [Fig. 4]. Over the east-central and eastern equatorial Pacific Ocean, low-level wind anomalies were easterly and upper-level wind anomalies were westerly. Convection remained enhanced over Indonesia [Fig. 5]. Collectively, the coupled ocean-atmosphere system in the tropical Pacific reflected ENSO-neutral.

The IRI predictions indicate ENSO-neutral is most likely through the Northern Hemisphere winter 2025-26 [Fig. 6]. In contrast, the North American Multi-Model Ensemble favors the onset of La Niña conditions during the Northern Hemisphere fall, though lasting a shorter duration than NOAA's requirement of five consecutive overlapping 3-month seasons. While the subsurface equatorial Pacific remains above average, easterly trade winds are predicted to strengthen in the coming month, which could portend cooler conditions. In summary, ENSO-neutral is most likely through the late Northern Hemisphere summer 2025 (56% chance in August-October). Thereafter, chances of La Niña conditions increase into the fall and winter 2025-26, but remain nearly equal to ENSO-neutral [Fig. 7].

This discussion is a consolidated effort of the National Oceanic and Atmospheric Administration (NOAA), NOAA's National Weather Service, and their funded institutions. Oceanic and atmospheric conditions are updated weekly on the Climate Prediction Center web site (El Niño/La Niña Current Conditions and Expert Discussions). A probabilistic strength forecast is available here. The next ENSO Diagnostics Discussion is scheduled for 14 August 2025.

To receive an e-mail notification when the monthly ENSO Diagnostic Discussions are released, please send an e-mail message to: ncep.list.enso-update@noaa.gov.