Published: Monday, 15 March 2021 05:57 March 15, 2021 - By Emily Becker - La Niña continues in the tropical Pacific, but it has weakened recently, and forecasters estimate about a 60% chance of a transition to neutral conditions in the late spring. Looking farther out into the fall of 2021, El Niño is unlikely to develop, and the chances of La Niña and neutral are similar. Migratory birds The February 2021 average sea surface temperature in the Niño3.4 region—our primary ENSO monitoring index—was just about the same as January, at about 1.0°C cooler than the 1991–2020 average, according to the ERSSTv5 dataset. (ICYMI: I covered the shift to the 1991–2020 average last month.) This comfortably exceeds the La Niña threshold of 0.5°C cooler than average.