DUBLIN – Record-breaking high temperatures are sweeping across Ireland and several European nations as an “extreme” meteorological event triggers a substantial build-up of atmospheric high pressure.
The phenomenon, described by experts as a blocking event, has trapped heat over northwest Europe, leading to provisional temperature records and the issuance of official weather warnings.
The current conditions are the result of a specific atmospheric configuration where a high-pressure system becomes stationary, preventing the usual movement of weather patterns and allowing heat to accumulate over several days.
The Mechanics of Atmospheric Blocking
Met Éireann, the Irish national meteorological service, reports that an intense area of high pressure has become “stacked up through the atmosphere,” creating a process of sinking air.
Paul Moore, a climatologist with Met Éireann, explained that this downward pressure suppresses the formation of clouds, which typically requires rising air. As the air is compressed, temperatures rise.
“Just think of pumping a tyre on a bicycle – it heats up because you’re causing the pressure to go up, and so the same thing happens in the atmosphere when you get high pressure over the same area, stacked through the atmosphere for a number of days over and over again,” Moore said.
“It keeps the pressure, the air keeps sinking down, and the temperature underneath keeps rising.”
Meteorologists refer to this as an atmospheric “blocking high,” a pattern that can stall over a region and, in summer, drive prolonged heat, while in winter it can lock in cold conditions. European forecasters have grown increasingly concerned about such blocks because they can overwhelm existing heat-response plans and strain power and transport systems across several countries at once.
Record Temperatures and Regional Warnings
A temperature of 28.6 degrees was recorded at Shannon Airport, provisionally breaking the record for the highest temperature documented in the month of May by Met Éireann. Moore indicated a “good likelihood” that this record would be surpassed as the blocking pattern persists.
In response to the extreme conditions, Met Éireann issued a status yellow high temperature warning for the following eight counties:
- Clare
- Kerry
- Limerick
- Tipperary
- Galway
- Kilkenny
- Laois
- Offaly
The status yellow notice, issued under the national public-warning system overseen by Met Éireann, is the first tier in a three-level scale that guides the response of local authorities, emergency services and health agencies to weather-related risks.
The national forecaster highlighted several immediate risks associated with the heat, including:
- Increased water safety risks due to higher usage of beaches and lakes
- Elevated potential for forest and gorse fires
- Heat stress, particularly for older people, outdoor workers and young children, and disrupted sleeping conditions
Similar warnings and record-breaking temperatures have been reported in France and the United Kingdom, where national meteorological agencies are also coordinating with health and civil protection authorities to prepare hospitals, care facilities and critical infrastructure for a surge in heat-related demand.
Climate Change and ‘Weather Whiplash’
Peter Thorne, director of the Icarus Climate Research Centre at Maynooth University, noted that while blocking events are meteorological occurrences, their intensity is being amplified by global warming.
“It’s an extreme event, and then you’ve just got climate change on top, which means when this does happen, it happens with more ferocity,” Thorne said.
Thorne described the rapid transition from the “Arctic air masses” that dominated much of May to the current “warm air mass” from the south as “weather whiplash.” According to Thorne, this volatility between temperature extremes is becoming a more frequent phenomenon due to climate change.
Scientists point out that such swings are consistent with broader European climate assessments and will test the capacity of governments to deliver on adaptation measures already set out in frameworks such as the EU Climate Adaptation Strategy and national climate action plans.
Public Health Risks and Infrastructure
The sudden spike in temperature presents significant risks to vulnerable populations, particularly those living in poorly ventilated homes and in urban areas with little shade or green space.
“Undoubtedly this extreme heat, particularly in houses that are poorly ventilated and are sun traps, will have an impact upon the most vulnerable in society. So, I would be surprised if, in the next week, we didn’t see a spike in death notices.”
Thorne warned that extreme heat creates “huge issues for morbidity, mortality, [and] huge challenges for our farmers.”
To mitigate these risks, Thorne recommended that residents increase ventilation in homes that trap heat and, where possible, avoid indoor temperatures rising through the hottest part of the day. He also suggested that government authorities implement or expand the use of community “cool spaces,” such as libraries and leisure centres, where the public can seek relief during peak temperatures.
Health officials are already urging people to check on elderly neighbours, avoid strenuous outdoor activity in the afternoon and follow guidance similar to that set out in the World Health Organization’s heat-health action plans. Farmers, meanwhile, are being advised to manage livestock exposure to direct sunlight and to monitor water supplies as soil moisture falls.
In the long term, Thorne suggested the necessity of exploring artificial cooling for residential housing and integrating heat resilience into building standards, urban planning and social housing policy. That would bring Ireland into closer alignment with European efforts to climate-proof homes, hospitals and schools as heat extremes become more common.
Despite the intensity of the heat, Met Éireann noted that the event does not technically qualify as a heatwave in the Republic, as that designation requires five consecutive days with maximum temperatures exceeding 25 degrees at the same station under its formal criteria.
The current spell is expected to end as low pressure moves into the region, but scientists and officials alike see the episode as an early-season warning of the pressures that more frequent and intense heat events will place on public health systems, emergency planning and long-term climate adaptation policy.
