Global forecast for 2025 sees temperatures falling back below 1.5°C

The average global surface temperature during 2025 will be between 1.29°C and 1.53°C – and most likely 1.41°C – above the pre-industrial average, according to a forecast by the Met Office, the UK’s national weather and climate service. That is slightly cooler than 2024, which is set to be the first calendar year to exceed 1.5°C.

“A year ago, our forecast for 2024 highlighted the first chance of exceeding 1.5°C,” Nick Dunstone of the Met Office said in a statement. “Although this appears to have happened, it’s important to recognise that a temporary exceedance of 1.5°C doesn’t mean a breach of the Paris Agreement. But the first year above 1.5°C is certainly a sobering milestone in climate history.”

The Paris Agreement set a goal of limiting warming to between 1.5°C and 2°C above a pre-industrial baseline. Most climate scientists now define the pre-industrial temperature as the average global surface temperature between 1850 and 1900, because this is the earliest period for which we have reliable direct measurements. However, several studies suggest that by that period, the world had already warmed significantly as a result of human activities.

The forecasted fall in surface temperature in 2025 will be a result of heat being transferred from the atmosphere to the oceans due to the La Niña phenomenon, and does not mean the planet as a whole has stopped warming. The overall heat content of the oceans and atmosphere continues to rise because of increasing carbon dioxide emissions from human activities leading to higher atmospheric levels of CO2.

During La Niñas, cooler waters rise up in the Pacific and spread across the surface, resulting in a net transfer of heat from the atmosphere to the oceans. During El Niños, the opposite happens. An El Niño in 2023 contributed to that year’s record-smashing surface temperatures, which were then exceeded in 2024. However, the El Niño alone does not fully explain the record temperatures.