When cooler temperatures and light rain arrive this week, they will not end the claims exposure this summer has created. They will begin a second phase of it. That is the point brokers placing property cover for clients on clay-rich ground, near heathland or woodland, or with older building stock need to understand before autumn takes hold.
The conditions driving two of this summer's most active claims categories - wildfire and subsidence - do not resolve when the weather changes. They convert into a different set of risks, and in the case of subsidence, one that has historically generated a claims surge that outlasts the drought that triggered it.
Wildfire has been building as a claims peril this summer in ways the UK market has not historically had to price. The Environment Agency has recorded 110 wildfires on Sites of Special Scientific Interest in 2026. On August 14, six fires broke out across the West Midlands within hours of each other. Homes in Stourbridge, Stoke-on-Trent, Birmingham, Warwickshire, and Worcestershire were destroyed or damaged.
Home insurers paid out £72 million in subsidence claims in the second quarter of 2026 based on figures from the Association of British Insurers (ABI). The average settled subsidence claim hit a record £20,000.
Wildfire has traditionally sat behind flood and subsidence in UK underwriting priority. Many standard property policies were not drafted with wildfire as a named peril. Whether a grass fire starting off the insured premises and spreading to a property triggers cover depends on specific wording. The answer varies across the market.
The longer-term exposure sits in the shift from drought to autumn rainfall. UK clay soils shrink and crack during extended dry periods. When sustained rain returns after prolonged desiccation, those soils swell. The result is structural movement in buildings on clay-rich ground: subsidence on the way down, heave on the way back up.
The current conditions fit a well-established pattern. The summers of 2018 and 2022 both produced subsidence surge years. According to actuarial firm Milliman, soil moisture deficit data from 2025 tracked conditions in line with both those years. ABI data puts 2025 subsidence payouts at a record £307 million.
Steven Coxon, head of subsidence at Claims Consortium Group, has identified three surge years since 2018. He noted that ground conditions at the start of 2026 had not recovered from the previous year's drought before the current dry spell began. That accumulated ground stress is what makes incoming autumn rain a claims trigger rather than simply a weather change.
The Building Cost Information Service (BCIS) published a warning in August that rising drought frequency is widening an underinsurance gap in property cover. Cos Kamasho, principal consultant at BCIS, said rising reinstatement costs, gaps in information at renewal and more frequent climate-related claims are converging. Policyholders, he warned, risk discovering their sums insured fall short only when a loss occurs. The ABI/BCIS House Rebuilding Cost Index shows domestic rebuilding costs rose 3.9% in the year to July.
Deloitte's UK home insurance analysis, published in late 2025, forecast that UK home insurers would swing to a net underwriting loss this year. The combined ratio is projected at 102.1%. That level of market pressure typically translates into tighter underwriting terms at renewal for exposed risks.
Brokers with clients on clay-soil ground, near heathland or woodland, or with older building stock have a narrow window. Cover should be reviewed before the autumn claims season takes hold. Three things are worth checking. First, whether wildfire is explicitly named or excluded in the property wording. Second, whether sums insured are adequate given a 3.9% rise in rebuilding costs over the past year. Third, whether excess structures on subsidence cover have been reviewed since 2022.
The Prudential Regulation Authority (PRA) launched its Dynamic General Insurance Stress Test in May to examine how the market would handle a coordinated market-wide claims shock. The end of one of the driest UK summers on record is not the end of the claims exposure it has created.
