What is causing record-breaking temperatures? Here is what you need to know

Ireland and other parts of Europe are facing record-breaking temperatures in late May, driven by an extreme meteorological event known as a blocking high-pressure system. Peter Thorne, director of the Icarus Climate Research Centre at Maynooth University, explained that this high-pressure area has remained stationary for several days, trapping heat and preventing cooler air from moving in. The phenomenon is exacerbated by climate change, intensifying the heat’s impact. Met Éireann climatologist Paul Moore described the situation as an intense high-pressure zone over northwest Europe, including Ireland, where sinking air suppresses cloud formation and compresses, raising temperatures. He compared the effect to pumping a bicycle tire, where increased pressure generates heat. The system has already pushed temperatures to 28.6 degrees Celsius at Shannon Airport, provisionally breaking Ireland’s May record, with further record-breaking heat expected on Tuesday. Met Éireann has issued a status yellow high-temperature warning for eight counties—Clare, Kerry, Limerick, Tipperary, Galway, Kilkenny, Laois, and Offaly—from midday Tuesday until 6pm Wednesday. The warning highlights risks such as water safety hazards, potential forest fires, heat stress, and poor sleeping conditions. Similar warnings have been issued across Europe, with record temperatures also reported in the UK and France. Despite the heat, Ireland has not yet experienced a heatwave, as defined by Met Éireann as five consecutive days with temperatures exceeding 25 degrees Celsius at a single station. Ireland had previously been under Arctic air masses, leading to cooler-than-average May temperatures, but a warm air mass from the south has shifted the pattern. Thorne warned of 'weather whiplash,' where rapid shifts between extremes become more common due to climate change, and cautioned that the current heat could result in deaths and severe challenges for farmers. The high-pressure system is expected to weaken by Thursday as low pressure moves in, potentially ending the hot spell. However, experts emphasize the long-term risks of such extreme weather events, which are projected to increase in frequency and intensity.