Hottest Jan ever as La Nina fails to moderate temps
January’s average surface air temperature reached 13.23°C, soaring 1.75°C above pre-industrial levels, according to data released on Thursday by the EU’s Copernicus Climate Change Service
Global temperatures shattered records again in the first month of this year as January became the warmest ever recorded, marking an unprecedented 18th month out of the last 19 that were above a critical climate threshold despite cooling La Nina conditions that typically moderate global heat.
January’s average surface air temperature reached 13.23°C, soaring 1.75°C above pre-industrial levels, according to data released on Thursday by the European Union’s Copernicus Climate Change Service. The reading breaches the 1.5°C threshold of warming that scientists warn could trigger catastrophic climate impacts if sustained.
Samantha Burgess, strategic lead for climate at the European Centre for Medium-Range Weather Forecasts, described January 2025 as “another surprising month, continuing the record temperatures observed throughout the last two years, despite the development of La Niña conditions in the tropical Pacific and their temporary cooling effect on global temperatures.”
The twelve-month period from February 2024 to January 2025 averaged 0.73°C above the 1991-2020 average and 1.61°C above the estimated 1850-1900 pre-industrial levels, intensifying concerns about meeting Paris Agreement targets aimed at limiting global temperature rise.
Regional temperature patterns revealed stark variations across the globe. While northeast and northwest Canada, Alaska, Siberia, southern South America, Africa, much of Australia, and Antarctica experienced above-average temperatures, significant below-average readings were recorded in the United States, easternmost regions of Russia (including Chukotka and Kamchatka), the Arabian Peninsula, and mainland Southeast Asia.
Experts said the trend could continue. “The La Nina is not strong enough to impact temperatures globally. Global warming trend is also very high. Similar records may continue for a few months,” said M Rajeevan, former secretary of India’s ministry of earth sciences and climate scientist.
La Niña — a cyclical phenomenon in which the waters in central and eastern Pacific are cooler than usual — brings broader changes to global weather patterns, affecting winds, pressure, and rainfall across the tropical Pacific. In regions like India, it typically brings stronger monsoons and colder winters, while its counterpart, El Niño, often leads to harsher summers and weaker monsoons. Generally, La Niña leads to lower average global temperatures.
Some experts said a weaker La Nina could be indicative of a stronger effect of the climate crisis – the long-term warming of the atmosphere. “Last month’s exceptional, record-breaking temperatures signal more than just the usual progression of global warming,” said Stefan Rahmstorf, professor of physics of the Oceans at the University of Potsdam. “This is the first time that temperatures recorded during a La Niña period in the tropical Pacific have exceeded those of a preceding El Niño period. This is of serious concern - over the past sixty years, all twenty five La Niña January’s have been cooler than surrounding years.”
Europe experienced its second-warmest January on record, with temperatures reaching 1.80°C, which was 2.51°C above the 1991-2020 average. Only January 2020 was warmer, at 2.64°C above average.
Ocean temperatures have raised red flags. January’s average sea surface temperature of 20.78°C ranked as the second-highest on record for the month, 0.19°C below January 2024’s record. While the central equatorial Pacific showed below-average temperatures, readings in the eastern equatorial Pacific were close to or above average, suggesting a potential slowing or stalling of the El Niño to La Niña transition. Unusually high temperatures persisted across many other ocean basins and seas.
This follows a broader pattern of ocean warming. A new international study published in Advances in Atmospheric Sciences on January 8, 2025, found new temperature records in six of eight investigated ocean regions: the Indian Ocean, tropical Atlantic, Mediterranean Sea, North Atlantic, North Pacific, and Southern Ocean.
The Arctic faced severe impacts, with sea ice extent dropping to its lowest January level on record, 6% below average and matching the previous low set in January 2018. Arctic sea ice concentration fell particularly low in the eastern Canadian sector, including Hudson Bay and the Labrador Sea, and in the northern Barents Sea. Antarctic sea ice showed relative stability at 5% below average, though concerns persist about long-term trends.
“Every country must treat this as a stark reminder about the urgent need to curb further temperature rises by redoubling efforts to phase out fossil fuels,” Rahmstorf added.
Sir David King, chair of the Climate Crisis Advisory Group and former UK Chief Scientific Advisor, called the data “the clearest warning yet that global warming has accelerated.”
“Our global weather systems are in transition and we have no international agreement on managing the earth system passing this overall tipping point,” King said. He emphasized the urgency of action, citing the UK’s recent commitment in Azerbaijan to reduce emissions by 81% by 2035 as “a start.”
King outlined a comprehensive response strategy: “We need every country to declare commitments to deeply and rapidly phase out their dependence on fossil fuels, going well beyond commitments made in Paris in 2015. We also need to publicly finance billions into techniques for efficient and safe removal of tens of billions of tons of excess greenhouse gases already present in the atmosphere, and techniques for stemming the loss of ice at both the North and South poles.”
King concluded with a warning about future impacts: “Every city, region, and country will need to develop and implement strategies for creating resilience against the range of extreme weather events that will continue to become more extreme over the coming decades.”