Sea surface temperatures off the northeast coast of England and to the west of Ireland were 3 to 4C above normal, Met Office analysis has found.

"The North Atlantic is experiencing record-breaking temperatures at present," Professor Stephen Belcher, the Met Office chief scientist, said.

"May 2023 has seen the highest temperatures of any May since 1850. But it doesn't stop here. It has also been the highest month above average compared with any individual month in the series."

Prof Belcher said an anomaly map for current sea surface temperatures in the North Atlantic, which compares current measurements with the average over a long-term period, showed "some areas really stand out".

"You can see that the eastern Atlantic, from Iceland down to the tropics, is much warmer than average. But areas around parts of northwestern Europe, including parts of the UK, have among some of the highest sea-surface temperatures relative to average.

"May 2023 was nominally the warmest May in the sea-surface temperature around the near-coastal waters of the UK since the late nineteenth century. The value is about 1.6C above the average for May over the period 1961-1990."

Global sea surface temperatures highest since 1850

Global sea surface temperatures in April and May were the warmest on record for those months since 1850, with temperatures around 1.25C above the long-term average, the Met Office said in its analysis.

It said the record-breaking temperatures were being driven by human-caused climate change and natural variation within the climate system.

Such natural variation is rising overall because of climate change, it added.

Professor Albert Klein Tank, the head of the Met Office Hadley Centre, said: "All of these elements are part of natural variation within the climate system which are coming together to elevate sea-surface temperatures to higher levels.

"It is not believed that these factors represent a climate-change-induced tipping point that produces runaway temperatures. However, they will add to climate and weather impacts this year."

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Antarctic sea ice lowest on record for June

In a separate report, the Met Office also found the extent of Antarctic sea ice was the lowest on record for June by a wide margin and has been at record or near-record lows since December 2022.

Dr Ed Blockley, the lead of the Polar Climate Group at the Met Office, said: "Over recent decades we have seen a sustained loss in Arctic sea ice extent in every month of the year, but especially in late summer to early autumn.

"Although the current Arctic sea ice extent is considerably higher than the record low for the time of year, it is still well below the long-term average.

"Antarctic sea ice has been at very low levels since November 2016. This year we have seen Antarctic sea ice shrink to a record low-point for the time of year, following a second successive annual record minimum sea ice extent in February."

Hottest ever start to June as global temperatures spike

It comes after the world experienced its hottest-ever first 11 days of June.

Earth's average air temperature was more than 1.5C hotter than before industrial times for the first time ever, according to the European Union's Copernicus Climate Change Service (C3S).

Almost every country in the world has committed to trying to limit permanent warming to 1.5C above pre-industrial levels, in a bid to make more manageable the dangerous impacts of climate change such as floods, rising sea levels, and droughts.