UK Cities Facing Increased Heat Vulnerability by 2100

By the Editorial Team · Monday, September 21, 2026

Several UK cities, including Leicester, Exeter, and Nottingham, are projected to see substantial increases in heat vulnerability by the end of the 21st century, with Portsmouth remaining the most at-risk city throughout. This rising heat threat poses significant challenges for public health, infrastructure, and emergency services, underscoring the urgent need for targeted urban planning and adaptation strategies.

Several UK cities are projected to experience significant increases in heat vulnerability by the end of the 21st century, according to a recent analysis based on the Ordnance Survey (OS) heat vulnerability index. The findings highlight shifting risks across urban areas as rising temperatures threaten public health and infrastructure.

Among the cities expected to face the largest escalation in heat-related risks between 2070 and 2100 are Leicester, Exeter, Nottingham, Brighton, and Bristol. Leicester is forecast to see the most notable increase, rising from 10th place in current heat vulnerability rankings to fourth by century’s end. Contrary to common assumptions that London bears the highest risk, Portsmouth currently tops the vulnerability index, followed by Carlisle, the City of Westminster, Newcastle upon Tyne, and Plymouth.

Projecting forward to the medium (2040-2070) and longer term (2070-2100), Portsmouth remains the city most vulnerable to overheating. The top 10 cities at risk during both periods include, in order: Portsmouth, City of Westminster, Plymouth, Leicester, Exeter, Nottingham, Bristol, Brighton and Hove, Cardiff, and the City of London.

The report also identifies cities with the greatest natural cooling capacity, serving as buffers against extreme heat. Milton Keynes ranks highest for natural cooling, followed by St Asaph, Durham, Dunfermline (tied with Tyddewi/St Davids), and Truro. Other cities showing lower risk currently include Abertawe (Swansea), Bangor, Ripon, Peterborough, and Inverness.

When examining heat vulnerability rankings for the medium term, the cities least at risk are St Asaph, Bangor, Tyddewi, Sheffield, Durham, Leeds, Stoke-on-Trent, Wakefield, Ripon, and Wolverhampton. In the longer term, the lowest risk cities shift slightly, with Bangor, Tyddewi, Durham, St Asaph, Sunderland, Inverness, St Albans, Milton Keynes and Preston (tied), Kingston upon Hull, and Liverpool occupying the bottom of the vulnerability scale.

Nick Bolton, CEO of Ordnance Survey, emphasized the importance of these findings, noting that urban centers house millions who are vulnerable to the adverse effects of extreme, sustained heat. He highlighted the impacts on health and wellbeing, housing and workplace comfort, as well as increased strain on transport, energy, and emergency services.

The UK has already experienced significant heat-related consequences this year. Between May and June, England recorded approximately 2,877 excess deaths attributed to heatwaves, nearly twice the total for the entire summer of 2025.

Despite some cities currently benefiting from stronger natural cooling, all are expected to meet “high vulnerability” criteria within the next five decades. Experts stress the need for proactive urban planning and development measures to mitigate these risks, alongside individual actions to adapt to changing climate conditions.

This article was reported by synthesizing coverage from multiple independent news outlets to present a balanced, unbiased account. Read about our editorial standards. Spotted an error? Let us know.