El Nino-Southern OScillation

NASA

A Subtle Return of La Niña

After a several-month hiatus, La Niña returned to the equatorial Pacific Ocean in September 2025 and has continued into December. However, this occurrence of El Niño’s cooler counterpart is relatively weak, and its influence on weather and climate over the next several months remains to be seen.   Part of the El Niño-Southern Oscillation (ENSO) cycle, La Niña develops when strengthened easterly trade winds intensify the…