Projected global heat to remain unrelenting until 2029 – Report
The 2025 Global Annual to Decadal Climate Update from the WMO forecasts that yearly global surface temperatures will range between 1.2 and 1.9 degrees Celsius above pre-industrial levels.
Global temperatures are expected to stay unusually high from 2025 through 2029, with a strong possibility that at least one of those years will become the hottest ever recorded, according to a new report by the World Meteorological Organisation (WMO).
The 2025 Global Annual to Decadal Climate Update from the WMO forecasts that yearly global surface temperatures will range between 1.2 and 1.9 degrees Celsius above pre-industrial levels, using the 1850–1900 period as a benchmark.
The report highlights an 80 per cent likelihood that one year in this period will overtake 2024, which is currently the hottest year on record.
"It is likely (80% chance) that at least one year between 2025 and 2029 will be warmer than the warmest year on record (currently 2024) and although exceptionally unlikely, there is now also a chance (1%) of at least one year exceeding 2°C of warming in the next five years," the report reads.
There is also an 86% chance that at least one year in the upcoming five-year period will see a global temperature rise above 1.5 degrees Celsius.
Additionally, the report gives a 70% chance that the average temperature over the full five years will exceed 1.5 degrees above the pre-industrial average.
This marks a sharp rise in projections. In the WMO’s previous report covering 2024 to 2028, the likelihood was 47%.
It was 32% in the report for 2023 to 2027.
The WMO warns that even slight increases in warming can trigger more severe climate impacts, including longer droughts, harsher heatwaves, more intense rainfall, faster melting of glaciers and sea ice, ocean heating, and rising sea levels.
Although the current long-term average remains below 1.5 degrees, short-term spikes are becoming more frequent.
The new report follows the WMO’s State of the Global Climate 2024 report, which showed that 2024 is likely the first full year to go beyond the 1.5 degree mark and confirmed it as the hottest year since records began 175 years ago.
Under the Paris Agreement, countries committed to keeping the rise in long-term global temperatures well below 2 degrees and to push toward a 1.5-degree limit.
Scientists continue to warn that crossing 1.5 degrees risks triggering far more dangerous climate events, with every fraction of a degree making a difference.
