The UK Health Security Agency (UKHSA) and the Met Office have jointly issued a heat-health alert alongside a three-day thunderstorm warning affecting various parts of the UK. This alert comes as temperatures are forecast to soar up to 30°C on Friday, June 13, 2025, driven by a “Spanish plume” of hot, humid air from continental Europe. Simultaneously, heavy rain and thunderstorms are expected to cause travel disruptions and localized flooding across Wales, Northern Ireland, and parts of England from June 12 to June 14. Authorities are urging vulnerable populations to take precautions amid these weather challenges.
Heat-Health Alert: Regions and Risks
Areas Under Alert and Duration
The heat-health alert, classified as yellow, covers the East of England, East Midlands, London, and the South East. It is active from 9pm on Thursday, June 12, until 8am on Sunday, June 15, 2025. Temperatures in these regions are forecast to reach highs of 30°C, marking the first significant heat event of the year.
Vulnerable Groups and Health Impacts
The UKHSA emphasizes that even moderate heat can adversely affect health, particularly among older adults aged 65 and above and individuals with pre-existing respiratory or cardiovascular conditions. The alert carries a risk score of seven, indicating a medium likelihood of low-level impacts on health and social care services. Heat stress can exacerbate conditions such as dehydration and cardiovascular strain, leading to increased healthcare demand.
Dr. Agostinho Sousa, Head of Extreme Events and Health Protection at UKHSA, highlighted the importance of sensible precautions during this period. He urged the public to monitor vulnerable friends, family, and neighbors, ensuring they stay hydrated and avoid excessive heat exposure.
Thunderstorm Warning: Scope and Expected Impact
Timing and Locations
In parallel, the Met Office has issued yellow thunderstorm warnings spanning three days, from Thursday, June 12, through Saturday, June 14. The warnings cover:
- Wales and Southwest England (midnight to 1pm on June 12)
- Northern Ireland (6am to 9pm on June 12)
- Southeastern England and East Anglia (3pm on June 13 to 6am on June 14)
Weather Conditions and Risks
Heavy rainfall is expected, with up to 40mm potentially falling within three hours, raising the risk of surface water flooding. Thunderstorms may bring hail, frequent lightning, and gusty winds, which could disrupt travel, especially train services, and cause short-term power outages.
Met Office Chief Meteorologist Neil Armstrong warned of the potential for localized flooding of homes and businesses, urging residents to remain vigilant. Deputy Chief Meteorologist Tony Wisson noted some uncertainty regarding the precise location and intensity of storms but stressed the importance of preparedness given the possible hazards.
Meteorological Causes and Broader Context
The heatwave and thunderstorms are driven by a southerly airflow that began on Wednesday, June 11, transporting warm, humid air from southern Europe into the UK. This “Spanish plume” phenomenon is known for triggering hot weather and unstable atmospheric conditions conducive to thunderstorms.
The UKHSA and Met Office’s coordinated heat-health alert system aims to provide early warnings to protect public health by alerting healthcare services and vulnerable populations to potential heat impacts. Heatwaves in the UK are becoming more frequent and intense due to climate change, increasing the urgency for effective public health responses.
Public Advice and Preparedness
Heat Precautions
Authorities recommend staying hydrated, avoiding strenuous outdoor activities during peak heat hours, wearing light clothing, and checking on vulnerable individuals. Heat affects the body by stressing the cardiovascular and respiratory systems, with dehydration and certain medications increasing risk.
Thunderstorm Safety
Residents in affected areas should prepare for potential flooding and power outages. It is advised to avoid driving through flooded roads, secure outdoor belongings, and stay indoors during lightning storms.
The British Red Cross has called for government prioritization of heat risk planning and enhanced support for vulnerable groups, emphasizing the growing health and wellbeing challenges posed by extreme weather.
