A yellow heat health alert has been declared for large swathes of England as forecasters warn that temperatures will surpass 30°C in parts of the country early this week, bringing with them an elevated risk of heat-related illness and wildfires.
The UK Health Security Agency (UKHSA) confirmed the alert will run from midday on Monday until 6pm on Wednesday, covering Yorkshire and the Humber, the East Midlands, East of England, London, the South East and the South West.
The first half of 2025 has produced a stark reminder that wildfire is no longer a strictly seasonal peril. Blazes from Dorset to Edinburgh and across continental Europe have underscored the shifting nature of the threat - and the scale of the insured losses now at stake.
Swiss Re Institute estimates global insured natural catastrophe losses at $80 billion for the period, the second-highest first-half total on record. Nearly half stemmed from two winter fires in California’s Los Angeles County, the Palisades and Eaton events, which destroyed more than 16,000 structures and generated an estimated $40 billion in claims.
While the UK’s recent incidents – the ongoing Dorset heathland blaze that consumed 69 hectares and forced the evacuation of 20 homes, and the gorse fire on Edinburgh’s Arthur’s Seat – are far smaller in scale, they echo a broader pattern. Hotter, drier conditions, strong winds and the encroachment of housing into high-risk landscapes are creating fire conditions outside traditional peak seasons. In both cases, emergency services warned of rapid flame spread and difficult suppression conditions, urging the public to keep away.
The fire season has been equally severe in southern Europe. In France’s Aude region, a blaze described by the prime minister as a “catastrophe on an unprecedented scale” razed 16,000 hectares - an area larger than Paris - killing one person and injuring dozens. Italian crews fought fires on Mount Vesuvius, while in Greece, tinder-dry conditions combined with strong winds to destroy more than 1,500 hectares southeast of Athens.
Such events illustrate the European dimension of wildfire risk. Swiss Re notes that droughts are becoming more frequent across the continent, lengthening fire seasons and complicating suppression through water scarcity.
For underwriters, the Palisades and Eaton claims now rank among the 10 costliest insured natural catastrophe events of any peril in modern records. Globally, wildfire has risen from contributing around 1% of insured nat cat losses before 2015 to around 7% over the past decade. Eight of the ten most expensive insured wildfire events have occurred in that time.
The drivers are familiar to UK insurers assessing domestic flood or storm exposures: rising asset values, urban expansion into hazard-prone zones, and climatic shifts altering hazard frequency and severity. In wildfire’s case, US data show exposure growth in the wildland–urban interface outpacing other zones by almost a factor of two.
Loss experience remains highly volatile year-on-year, and Swiss Re cautions that “more and rising associated insured losses can be expected” as settlement patterns and lengthening fire seasons converge. For 2025, the institute projects that total insured catastrophe losses could approach $150 billion, with the peak of the Atlantic hurricane season still to come.
For the UK market, the lesson from Dorset’s heathlands and Arthur’s Seat is not that such fires will match Californian or Mediterranean loss levels in insured terms, but that the hazard profile is changing. As one Dorset incident commander put it, conditions were such that “anyone trying to see what’s going on could be cut off very easily” – a reminder that rapid-onset fire is not solely a foreign peril, and that coverages, accumulation controls and risk modelling need to adapt accordingly.
