‘Unexpected’: January Breaks Temperature Record Globally, Startling Scientists

The emergence of a weather pattern associated with a temporary cooling of global temperatures did not bring down temperatures in January as scientists expected.

—

January stood out as an anomalous month in temperature terms, becoming the hottest January ever recorded despite the arrival of a cooling weather pattern.

Last month’s surface air temperature of 13.23C was 0.79C above the 1991-2020 average for January, the European Union-led Copernicus Climate Change Service (C3S) announced on Thursday as it described the event as “surprising.”

The recent development of La Niña conditions in the tropical Pacific had scientists believe global temperatures would slowly drop after the planet recorded its hottest year on record in 2024. The weather pattern, which typically occurs every three to five years, is associated with the periodic cooling of ocean surface temperatures in the central and east-central equatorial Pacific. It comes after another weather pattern, known as El Niño, pushed temperatures “off the chart” in 2023 and last year.

January’s measurements are therefore “surprising,” as Samantha Burgess, Strategic Lead for Climate at the European Centre for Medium-Range Weather Forecasts, put it.

“[M]any of us expect that 2025 will be cooler than both 2023 and 2024, and is unlikely to be the warmest year in the instrumental record,” climatologist Zeke Hausfather wrote in a blog post on Monday. Their expectations were not met, he went on to say, describing how last beat the prior record set in January 2024 “by a sizable margin.”

“January 2025 stands out as anomalous even by the standards of the last two years,” Hausfather wrote. “[A]t least at the start of the year nature seems not to be following our expectations.”

1.5C Is ‘Dead’

Last month also marked the 18th month in the last nineteen months for which the global-average surface air temperature was higher than 1.5C above the pre-industrial level. And 2024 was the first year on record to surpass the 1.5C mark.

The critical threshold was established at the 2015 COP21 climate summit, when 196 parties signed the legally binding Paris Agreement. They agreed to keep limiting global warming to below 1.5C or “well below 2C” above pre-industrial levels by the end of the century. Beyond this limit, experts warn that critical tipping points will be breached, leading to devastating and potentially irreversible consequences for several vital Earth systems that sustain a hospitable planet.

While recent developments do not signal a permanent breach of the critical limit, which scientists say is measured over decades, it sends a clear warning to humanity that we are approaching the point of no return much faster than expected. In fact, the United Nations estimates that current emissions reduction pledges put the planet on track for a temperature increase of 2.6-3.1C over the course of this century.

Scientists are not optimistic either. A survey of 380 IPCC scientists conducted by the Guardian last May revealed that 77% of them believe humanity is headed for at least 2.5C of warming.

And on Monday, renowned climatologist James Hansen said even the 2C target “is dead” after his latest paper concluded that Earth’s climate is more sensitive to rising greenhouse gas emissions than previously thought. The former top NASA climate scientist famously announced to the US Congress in 1988 that global warming was underway.⁣

Featured image: C3S/ECMWF.