The global average temperature in May this year was the second-highest on record, data showed. Some experts say that if a strong El Niño forms in the second half of the year, this year could surpass the record set in 2024, the hottest year on record.
The Copernicus Climate Change Service, part of the European Union, said Tuesday that the average global surface temperature last month reached 15.81 degrees Celsius. That was the second-highest May temperature, behind May 2024, the hottest on record.
Last month's temperature was 0.55 degrees higher than the May average for 1991 to 2020, and 1.42 degrees higher than the average for the pre-industrial period of 1850 to 1900.
Unusual heat waves continued across Europe. In the latter part of last month, hot air drawn in from North Africa moved north through the Mediterranean into Europe, then lingered under the influence of a high-pressure system, sending temperatures sharply higher across southern and western Europe.
Portugal, the United Kingdom and France set new May high-temperature records, and some areas saw temperatures fluctuate around 40 degrees. In Spain, the heat wave last month killed 101 people, the highest death toll since related statistics began being compiled in 2015.
The oceans were also far warmer than usual. According to the institute, the average sea surface temperature between 60 degrees south and 60 degrees north last month was 20.90 degrees. That was the second-highest figure, behind the record 20.93 degrees in May 2024.
The institute explained that sea surface temperatures remain unusually high across large parts of the tropical Pacific. The World Meteorological Organization (WMO) projects an 80% chance of an El Niño occurring between June and August this year.
An El Niño is judged to have begun when the sea surface temperature in the eastern Pacific monitoring zone remains at least 0.5 degrees above normal on a three-month moving-average basis for more than five months. The most recent El Niño began in June 2023 and lasted about a year.
Climate experts believe that a so-called "super El Niño," in which sea surface temperatures in the monitoring zone are more than 2 degrees above normal, could further fuel a rise in the global average temperature. As a result, some forecasts say the possibility that this year will be recorded as the hottest on record cannot be ruled out.
