July 13, 2026

expert reaction to modelling study of deaths in England and Wales during the heatwaves of May and June

A modelling study carried out by Grantham, the Met Office, and LSHTM looks at deaths during the heatwaves in May and June. 

Dr Gavin Stewart, Reader in Interdisciplinary Evidence Synthesis at Newcastle University, said:

“The estimates of excess mortality due to heat are based on established methods but uncertainties surrounding analysis of observational data  and deriving appropriate counter-factuals result in considerable uncertainty. The authors acknowledge some of this uncertainty in their paper and provide confidence intervals spanning 22% to 75% for their estimates which are more informative than the point estimate.  Incorporating all the uncertainty in these estimates would widen the range further, but it is clear that it is unlikely to be a trivial population level effect and the implications for climate mitigation and adaption are unambiguous.”

Dr Ana Raquel Nunes, Associate Professor in Health and Environment, Warwick Medical School, University of Warwick, said:

“This analysis presents estimates that carry uncertainty, rather than counted deaths. The most credible and policy-relevant finding is that the estimated death rate in the Midlands was comparable to the hotter south. This is consistent with evidence that protective capacity is unevenly distributed, and that populations less exposed to extreme heat hold fewer assets to cope with it, strengthening the case for targeted adaptation.”

Dr Akshay Deoras, Senior Research Scientist at the National Centre for Atmospheric Science & Department of Meteorology, University of Reading, said:

“Heatwaves are no longer just a summer inconvenience – they are a growing public health hazard in the UK. This is a robust study that uses well-established methods to estimate the health impacts of extreme heat and the contribution of climate change. Whilst the figures are modelled estimates rather than directly observed deaths, the central finding is consistent with a strong body of evidence: climate change is turning heatwaves into more dangerous events, with growing consequences for public health. 

“As with all modelling studies, there is uncertainty around the precise numbers, and the estimates cannot distinguish between deaths directly caused by heat and those brought forward by days or weeks in people who were already vulnerable. The precise numbers may change, but the direction of travel is clear: hotter summers will mean more heatwaves and greater health risks in the UK, unless we adapt and cut down the emission of greenhouse gases.”

‘Climate change increases heat-health risks from 2026’s May and June heatwaves’ by Clair Barnes et al.was released at 00.01 UK time on Monday 13 July

Declared interests

Akshay Deoras: “I’ve no conflict of interests to declare.”

Ana Raquel Nunes: “No conflicts of interest.”

For all other experts, no reply to our request for DOIs was received.