Earth just sweated through its record hottest June and 2023 could become the planet’s warmest year, according to newly released data.
June’s globally averaged surface temperatures – including those over both land and ocean – were warmer than any year since 1940, according to data from the European Centre for Medium-Range Weather Forecasts (ECMWF).
This topped the previous record warm June in 2019, and was about 2.5 degrees Fahrenheit above pre-industrial (mid- to late 19th century) levels, according to Zeke Hausfather, a climate scientist at Berkeley Earth.
Surface temperature anomaly for June 2023 relative to the 1991-2020 average for the globe and for western Europe.
Oceans drove the record warm June. Sea surface temperatures over the planet’s oceans were by far the warmest of any June in records since the mid-19th century. In fact, the ocean warmth was the most above average of any single month since 1900, according to Brian Brettschneider, an Alaska-based climatologist.
One factor contributing to this record warmth was an intensifying El Niño, the periodic warming of a strip of the equatorial Pacific Ocean.
Another was the exceptional, widespread warmth in the eastern and tropical North Atlantic Ocean. Weaker than usual subtropical high pressure led to lighter trade winds that didn’t allow the usual cooler water to upwell – or move up – to the surface in the tropical North Atlantic Basin.
There was also a lack of typical exhalations of dust-laden air from the Sahara Desert westward over the tropical Atlantic in June. Less airborne dust to reflect the sun’s energy would also contribute to warmer than average water in the tropical North Atlantic.
As the graph below shows, since late April, a section of the eastern North Atlantic Ocean has been record warm for that time of year than any previous year since 1979.
Several countries had their record hottest June. Among these included the United Kingdom, Ireland, Belgium and the Netherlands. The U.K. topped its previous hottest June, in records dating to 1884, by about 1.6 degrees Fahrenheit. In the realm of national temperature data compiled from numerous observing stations over a month’s time, that’s a pummeling of a previous record.
Canada also sweltered through a record hot June, which followed their record hot May, according to Brettschneider. That’s one driver of the country’s most widespread wildfire years in modern times.
China, France and Japan narrowly missed their record hottest Junes.
The past two Junes are now the two hottest on record in China. France fell just shy of their hottest June from 2003, the summer in which heat waves claimed an estimated 15,000 lives in the country, and at least 70,000 in Europe.