The global temperature for January-September is also 1.4 degrees Celsius higher than the pre-industrial average (from 1850-1900), the institute added. Climate change is pushing global temperatures to new records, and short-term meteorological models are also influencing temperature trends.

The previous month marked the warmest September ever recorded worldwide, with a temperature exceeding the average for the same month over the period 1991-2020 by 0.93 degrees Celsius. Within the ERA5 dataset, which extends back to 1940, the global temperature for that month was the most unusual warm month in any given year.

Climate scientists have affirmed that the recent record temperatures are a result of the interplay between climate change and the emergence of this year's El Niño weather phenomenon, which elevates the temperature of the surface waters in the eastern and central Pacific Ocean.

"The remarkable temperatures observed in September during this time of the year, following a summer of record-breaking heat, have shattered records with extraordinary significance. This extreme month has led to 2023 earning the concerning distinction of becoming the hottest year on record, with temperatures surpassing pre-industrial averages by approximately 1.4 degrees Celsius", said Samantha Burgess, Deputy Director of Copernicus, in a statement.

"Two months away from COP28, the sense of urgency for ambitious climate action has never been more critical", she said, referring to the United Nations Conference on Climate Change.

Last year was not a record, even though the world was 1.2 degrees Celsius warmer than in the pre-industrial period. The previous records were held by the years 2016 and 2020, when temperatures averaged 1.25 degrees Celsius higher.

According to Copernicus, the average sea surface temperature for September within the region spanning from 60°S to 60°N reached 20.92 degrees Celsius, marking it as the highest temperature ever recorded for the month of September and the second highest across all months, following August 2023.