Record January heat suggests La Niña may be losing its ability to keep global warming in check

January 2025 was the hottest on record—a whole 1.7°C above pre-industrial levels. If many climate-watchers expected the world to cool slightly this year thanks to the natural "La Niña" phenomena, the climate itself didn't seem to get the memo. In fact, January 2025's record heat highlights how human-driven ocean warming is increasingly overwhelming these natural climate patterns.