The mystery of the missing La Niña continues – and we don’t know why

An expected shift to cool La Niña conditions in the Pacific Ocean has been delayed again. Forecasters now project only a weak event to emerge by the end of November, which is likely to limit the cooling influence of the climate pattern on global average temperatures.

“I do not know why it has slowed down,” says Michelle L’Heureux at the US National Oceanic and Atmospheric Administration (NOAA). “If someone did, we might have been able to predict it.”