June was exceptionally warm for the time of the year in the global surface ocean, with a large contribution of extremely high temperatures for June in the North Atlantic and the Southern Ocean.
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In terms of surface air temperature, June 2023 was also the warmest June globally by a large margin at 0.53°C above average, according to the latest monthly bulletin of the Copernicus Climate Change Service (C3S).
The June update includes an analysis of the extreme warmth in the North Atlantic Ocean, and in particular the northeastern Atlantic that was 1.36°C above average for the month, and a combination of factors that likely contributed to this unprecedented situation. The waters around Ireland and the U.K. saw extreme marine heatwaves. In the Pacific Ocean, the El Niño event continued to develop.
The global surface air temperature was also the highest ever recorded for the month of June, significantly warmer than the previous warmest June, in 2019. Northwest Europe saw record temperatures for the month and parts of Canada, Mexico, Asia and eastern Australia were significantly warmer than normal.
The monthly C3S update for June Hydrological Variables shows wetter than average conditions over most of southwestern Europe, after a long series of very dry months. It was wetter than average also in northwestern Russia, and heavy precipitation led to flooding in Turkiye, Kosovo and Romania.
Parts of Canada, the United States, Mexico, Asia, and eastern Australia were significantly warmer than normal. It was cooler than normal over western Australia, the western United States, and western Russia.
Elsewhere, the drier-than-average conditions over much of North America favoured and sustained severe wildfires.
The Antarctic Sea ice extent reached its lowest extent for June since the beginning of satellite observations, at 17% below average. The daily Antarctic sea ice extent remained at unprecedented low values for the time of the year. The Arctic sea ice extent was slightly below average but significantly above the levels of the past eight years.
Antarctic sea ice reached its lowest extent for June since satellite observations began, at 17% below average, breaking the previous June record by a substantial margin.
Throughout the month, the daily Antarctic sea ice extent remained at unprecedented low values for the time of year. Sea ice concentrations were most below-average in the northern Weddell, eastern Bellingshausen, and northern Ross Seas while above-average concentrations continued to prevail in a broad Amundsen Sea sector.
Arctic sea ice extent was slightly below average but well above the June values from the past eight years. Above-average sea ice concentrations occurred in the Beaufort, Chukchi, and Greenland Seas and below-average concentrations in the Barents Sea, western Kara Sea, and Hudson Bay. ■