Global surface temperature is the average temperature of the Earth’s surface at a given time. It is a combination of the near-surface air temperature over land and the sea surface temperature, weighted by their respective areas. Global temperature records, using modern instruments for consistent worldwide data, officially began in 1880. So, there is nearly a 150-year continuous record.
For the first 11 months of 2025, the global surface temperature was 1.48 degrees Celsius (or 2.66 degrees Fahrenheit) above the pre-industrial reference temperature. It was 0.6 degrees Celsius above the 1991-2020 average. This puts 2025 on track to end up as either the second or third hottest year on record, continuing the strong warming trend the world has seen in the past decade.
This warming trend is striking. The ten warmest years in the record (which actually goes back to 1850, including years when the methodology was not as advanced) have in fact been the last ten years. The warmest year in the century-and-a-half record was 2024.
One has to understand that the global mean temperature is not like the local temperature where you live. Raising or lowering the local temperature by a degree or two is scarcely noticeable. Raising the global temperature by a degree means the atmosphere can hold 7% more moisture. That has major implications for rainfall and weather in general.
As civilization continues to dump more and more greenhouse gases into the atmosphere, the warming will continue, and new records will continue to be set. The consequences will not be good.
