January 2026 ranked as the fifth warmest January globally, even as large parts of Europe and North America endured an intense cold spell driven by a highly unstable Arctic jet stream, according to the European Centre for Medium-Range Weather Forecasts’ Copernicus Climate Change Service (C3S).
The global average temperature for the month was 1.47 degrees Celsius above the pre-industrial average (1850–1900), making it 0.28 degrees Celsius cooler than the record-breaking January 2025 anomaly of 1.75 degrees Celsius. Despite frigid conditions across parts of the Northern Hemisphere, extreme heat in the Southern Hemisphere and persistently warm oceans kept global temperatures among the highest on record.
Throughout January, a wavier-than-normal Arctic jet stream dominated weather patterns in the Northern Hemisphere. This instability, linked to rapid Arctic warming, allowed cold Arctic air to plunge southwards into Europe, North America and Siberia.
As a result, Europe recorded its coldest January since 2010, with an average land temperature of minus 2.34 degrees Celsius. Widespread cold conditions affected Fennoscandia, the Baltic States, eastern Europe, Siberia and the central and eastern United States. Heavy snowfall accompanied the freezing air masses in many regions.
Ironically, while Arctic air spilled southward, the Arctic itself was significantly warmer than average. Particularly high temperature anomalies were recorded in the Canadian Arctic Archipelago, Baffin Bay, Greenland and parts of the Russian Far East.
In stark contrast, the Southern Hemisphere experienced extreme summer heat. Southern South America, northern Africa, central Asia, much of Australia and Antarctica saw temperatures far above normal. These conditions triggered intense and widespread heatwaves, as well as wildfires.
In southeastern Australia, wildfires that erupted during the second week of January were found to be five times more likely and 1.6 degrees Celsius hotter due to human-induced climate change, according to an analysis by the World Weather Attribution consortium.
Despite the cold spells on land in the Northern Hemisphere, sea surface temperatures remained exceptionally high. The global average sea surface temperature between 60 degrees south and 60 degrees north was 20.68 degrees Celsius the fourth highest on record.
Large areas of the subtropical and northeast North Atlantic, including the Norwegian Sea, recorded their warmest sea surface temperatures for January. Parts of the North Pacific were also warmer than average, while temperatures in the central and eastern Pacific remained near normal due to weak La Niña conditions.
The warmer-than-normal Arctic conditions contributed to reduced sea ice coverage. Arctic sea ice extent in January 2026 was six per cent below average, marking the third-lowest extent for this time of year.
Sea ice concentrations were significantly below average in the northern Barents Sea, between Svalbard and Franz Josef Land, as well as in Baffin Bay and the Labrador Sea areas that also experienced unusually high surface air temperatures.
Beyond temperature extremes, January also brought heavy rainfall and flooding to several regions.
Western, southern and eastern Europe experienced wetter-than-normal conditions. Extreme rainfall led to flooding in the Iberian Peninsula, Italy, the western Balkans, Ireland and the United Kingdom.
Other regions with above-average rainfall included western Canada, northern Mexico, the southern United States, central Asia, eastern Russia, Japan, southeastern Brazil, northern Australia and southern Africa.
In southern Africa, intense rainfall caused severe flooding in parts of Mozambique, Eswatini, northeastern South Africa and Zimbabwe. The floods killed around 200 people and affected thousands more. An analysis by the World Weather Attribution consortium highlighted the urgent need for improved, Africa-specific weather and climate models to better understand and prepare for such extreme events.
The contrasting extremes of January 2026 bitter cold in parts of the north and intense heat in the south underscore the complex but persistent signals of global warming. Even as regional weather patterns fluctuate, rising global temperatures, unusually warm oceans and diminishing sea ice continue to reflect the broader and ongoing impacts of climate change.