NASA, NOAA, and the UK Met Office jointly confirmed on Thursday that the current year is the warmest in the 175-year global instrumental temperature record, with a global mean temperature 1.7 degrees Celsius above pre-industrial levels — surpassing the previous record, set in 2023, by 0.14 degrees Celsius.
The confirmation followed twelve consecutive months in which global average temperatures exceeded any previously recorded value for the corresponding calendar month. Each of the twelve monthly records was verified independently by all three agencies. The dataset supporting the determination was drawn from more than 20,000 surface weather stations and ocean buoys worldwide, maintained by the three agencies through independent methodologies. "Twelve consecutive months is not a statistical artefact," said a Met Office climate scientist who worked on the joint analysis. "Each of those months was individually the warmest ever recorded for that calendar month. Collectively they describe a system that has moved into new territory."
NASA, NOAA, and the Met Office built their temperature records independently of one another, using different approaches to quality control, gap-filling, and uncertainty quantification. The convergence of all three on the same annual record was described by climate researchers as the most significant aspect of the joint confirmation. "When three institutions that built their datasets entirely separately all arrive at the same answer, the probability that a shared methodological error is responsible approaches zero," said a climate scientist at Columbia University's Lamont-Doherty Earth Observatory.
A group of atmospheric scientists had filed a formal reanalysis request earlier in the week, arguing that a divergence between satellite measurements and surface station records introduced uncertainty into the record claim. Both NASA and NOAA acknowledged receipt of the request and noted that satellite instruments measure different atmospheric layers than surface stations and carry their own calibration uncertainties. The agencies said their surface station methodology remained the internationally agreed standard for surface temperature assessment.
Ocean heat content data, drawn from the Argo float network — a global array of autonomous ocean profilers — recorded new record values this year, providing an independent corroboration of the surface record that is not subject to the urban heat island effects sometimes cited as a concern for land-based stations.
A strong El Niño event has contributed to this year's anomaly, and the agencies were transparent about that contribution in their joint announcement. They noted, however, that the excess above the 2023 record was larger than El Niño alone would be expected to produce. "Natural variability is part of the story this year," the joint statement read. "It is not the whole story."
The joint confirmation was issued four days before the opening of an international climate summit at which the annual temperature assessment was expected to provide the evidential backdrop for discussions on emissions reduction commitments.