The Northern Hemisphere was hit by severe cold waves in the final weeks of January as a polar jet stream blew icy air into Europe and North America, according to the Copernicus Climate Change Service.

But monthly temperatures were above average over much of the globe, including in large parts of the Arctic and western North America, according to Copernicus.

"January 2026 delivered a stark reminder that the climate system can sometimes simultaneously deliver very cold weather in one region, and extreme heat in another," said Samantha Burgess, strategic lead for climate at the European Centre for Medium-Range Weather Forecasts (ECMWF).

The average global temperature in January was 1.47C above preindustrial times.

Europe endured its coldest January since 2010, with an average temperature of -2.34C, the service said.

The United States, meanwhile, was hit by a monster winter storm that dumped snow and crippling ice from New Mexico to Maine. It was linked to more than 100 deaths.

The planet remains in an extended run of human-driven warming, with 2024 setting a record high, 2023 ranking second 2025 now third warmest.