La Niña is a part of the El Niño southern oscillation, a climate fluctuation that slowly sloshes vast bodies of water and heat between different ocean basins and disrupts weather patterns around the world.

The past two years have seen month after month become the planet's hottest recorded. Climate scientists say human-produced greenhouse gases account for the majority of the warming.

Last month was the world's warmest January on record, continuing a streak of extreme global temperatures despite a shift towards the cooling La Niña weather pattern, scientists said.

By Shanna Hanbury January 2025 was the warmest January on record, surpassing the previous record set by January 2024, according to satellite data from the EU’s Copernicus program. The findings were unexpected as ongoing La Niña conditions in the Pacific typically cool down global temperatures.