The Met Office is reporting northwest European waters are currently experiencing an extreme marine heatwave, with sea surface temperatures (SSTs) reaching record highs for April and May since satellite monitoring began in 1982.

The Met Office is today bringing together the UK and Irish research community with Defra at Reading University to discuss science and research ongoing in UK marine heatwaves.

Now lasting over two months, the current event is significant due to its intensity and persistence. Current sea surface temperatures are warmer by up to 4°C west of Ireland, and by 1.5-2.5°C around the UK coastline: temperatures are what would usually be expected around mid-June.

The heatwave is the result of several overlapping factors. Prolonged high-pressure systems brought a dry, sunny spring and weak winds and waves, creating ideal conditions for warming. This means the sea started to warm mid-February, one month earlier than usual.

Additionally, the waters around the UK were already warmer than usual coming out of winter, a trend that has been building over the past 40 years, with an average increase of 0.3°C per decade.

Marine heatwaves in UK waters usually last around two to four weeks. However, this year’s event began early March and has continued into May, making it one of the longest on record for this time of year. The North Sea has already peaked in temperature, while areas west of Ireland and the Celtic Sea are currently experiencing their highest levels.

The prolonged warming can also amplify land heatwaves by reducing the cooling effect of sea breezes and by altering rainfall patterns.

Dr Jonathan Tinker, marine climate scientist, said:

"With projections suggesting UK summer sea temperatures could rise by up to 2.5°C by 2050, such events are likely to become more frequent, intense and longer-lasting. Marine heatwaves offer a glimpse into how changing ocean conditions could shape future weather conditions."