UK Railways: From Extreme Weather Response to Long-Term Adaptation
CPCS Senior Consultant Chris Webster examines how climate change is reshaping Britain’s railway and the growing challenge of balancing infrastructure resilience with operational performance.
The article draws on insights developed through CPCS’s climate adaptation work with Professor Brian Haddock, a former Head of Seasonal and Weather Resilience at Network Rail and one of the UK’s leading specialists in rail weather resilience and climate change adaptation, to explore how the industry can move beyond reacting to extreme weather and towards a more integrated approach to climate adaptation.
Climate adaptation is not just an engineering challenge.
It is a whole-system challenge that requires integrating climate risk into asset management, maintenance, renewal planning and operational decision-making to keep the railway safe, reliable and resilient.
This summer has put the relationship between extreme weather and rail infrastructure under scrutiny.
Against a backdrop of repeated heatwaves, low rainfall and increasingly dry ground, two passenger trains derailed within 24 hours at Lewes and Wickford. The incidents remain under investigation, and the role of the weather has not been established, but they occurred at a time when high temperatures were already affecting the operation of the network. Network Rail had introduced speed restrictions and other operational measures in response to heat and dry ground.
By 1 July 2026, Network Rail had already recorded 864 Critical Rail Temperature speed-restriction incident-days in 2026/27, more than the 803 recorded across the whole of 2025/26. These restrictions are an important means of managing immediate safety risk, but their increasing use also illustrates the growing operational consequences of extreme weather.
The derailments should therefore not be considered simply as isolated infrastructure failures, but in the context of the increasingly challenging conditions in which the railway is operating. By July, the Met Office, UK’s national weather and climate service, had recorded an unprecedented run of high temperatures, while half of England had been declared in drought following very low rainfall and exceptional heat.
These conditions affect more than the temperature of the rail itself. Sustained heat and falling soil moisture can change the behaviour of the ground supporting the railway, while hotter and drier conditions can also increase the risk from vegetation and lineside fire, even if these remain a smaller part of the overall risk facing the network.
Dry conditions can also create vulnerabilities when returns. Hard and desiccated ground can absorb water less effectively, increasing surface runoff during intense rainfall and placing additional pressure on drainage, earthworks and other vulnerable infrastructure.
The wider significance for rail lies in the changing environment in which the infrastructure has to perform.
Operational responses such as additional inspections, speed restrictions and closer monitoring are essential when extreme conditions occur. Used reactively, these measures protect the railway during the immediate event. Network Rail’s Extreme Heat Task Force has itself concluded that the railway’s operational response to extreme heat has historically been too reactive, highlighting the need to use forecasts and known vulnerabilities to plan the service and deploy resources before extreme conditions occur.
Adaptation therefore needs to reduce the need for operational intervention where possible, while planning in advance for the service that can safely and reliably be provided when restrictions remain necessary. Climate adaptation requires changing environmental conditions to be reflected in the way infrastructure is assessed, maintained, renewed and designed, and in how the railway plans and operates its services.
The Challenge: A Railway Facing New Climate Risks
Rail infrastructure is particularly exposed to the challenges of climate change because of the length of time assets remain in service. Track, drainage and electrical systems can operate for decades, while bridges, tunnels and earthworks can remain part of the network for considerably longer.
During those lifetimes, the environmental conditions those assets experience may become very different from those for which they were originally designed.
Infrastructure is designed and managed around assumptions about its operating environment. Drainage reflects expected rainfall, earthworks respond to groundwater and soil moisture, and track and overhead equipment operate within established temperature parameters. Climate change progressively alters those underlying conditions, exposing assets to stresses that may differ from those anticipated when they were designed or last renewed.
More extreme weather does not translate into a uniform increase in risk across the railway. Climate risk develops through the interaction between the environmental hazard, the exposure of the infrastructure and its vulnerability. The same period of extreme heat or intense rainfall can have very different consequences depending on the location, design and condition of the asset concerned.
Therefore, effective adaptation requires moving from broad climate projections to an understanding of risk at individual assets and locations. Higher temperatures or heavier rainfall indicate how the operating environment is changing, but decisions on where to intervene depend on where those hazards coincide with exposed or vulnerable infrastructure and could affect safety, performance, availability or the service experienced by passengers.
The Reality: Why Some Assets Fail Before Others
Asset condition is central to this picture. Weather frequently exposes existing weaknesses rather than creating failure in isolation. Drainage with reduced capacity leaves track and earthworks more vulnerable to intense rainfall. Deteriorating earthworks can be more sensitive to changes in soil moisture. Poor track geometry can increase sensitivity to thermal stress. The condition of an asset can therefore act as a multiplier of climate risk.
This has an important implication for adaptation in that greater resilience is not always about building new infrastructure. Often the first priority is to ensure existing assets perform as intended and focus maintenance where deteriorating condition and increasing climate exposure combine to create the greatest risk.
That requires a more local understanding of risk. A temperature threshold or rainfall warning applied across a large area can provide useful operational guidance, but the significance varies according to factors such as topography, soil type, drainage and asset condition. The value comes from translating wider weather and climate information into asset-specific and location-specific decisions that can inform both asset management and operational decision-making.
This summer provides an example. Network Rail has already had to respond to sections of track affected by shrinking peat and clay following prolonged heat and low rainfall, with speed restrictions and timetable changes. These maintain safe operation but also affect journey times, timetable performance and the service operators can provide. Climate risk therefore emerges from the interaction between weather, infrastructure and operations, rather than from the environmental hazard alone.
The Response: Understanding and Managing Risk
In practice, adaptation is a continuous cycle: understand vulnerability, target interventions, monitor changing risk and learn from what happens.
Adaptation starts with understanding where the railway is vulnerable. Incident, defect and maintenance records can identify recurring weather-related problems, while linking these with meteorological information can reveal the conditions under which they occur. This needs to reflect actual asset condition and degradation, rather than relying only on original design specifications or assumed performance.
That evidence can shape both maintenance and operational decisions. Heat-sensitive locations can receive greater attention ahead of high temperatures, drainage inspections can target sites where intense rainfall would have the greatest consequences, and earthworks can be monitored according to condition and exposure. Combining asset data with recent and forecast weather allows these decisions to change dynamically as risk develops.
For example, an earthwork already known to be in poor condition could receive additional inspection or monitoring following several unusually dry weeks if intense rainfall is forecast, or trigger a different operational response at that location.
The important point is that these measures form part of the same adaptation process. Better evidence identifies vulnerability. Targeted maintenance reduces it. Monitoring establishes whether risk is changing. Physical intervention follows where necessary. Operational planning determines how the railway manages the residual risk that remains. The experience of each weather event then feeds back into future planning rather than being treated as an isolated operational problem.
These measures form part of the same process whereby evidence identifies vulnerability, maintenance and physical intervention reduce it, monitoring shows how risk is changing, and operational planning manages the residual risk. Lessons from each event can then inform the next round of decisions.
The Future: Building a More Resilient Railway
Climate adaptation is most effective when asset management and operations are considered together, rather than as separate responses to extreme weather. Rail assets are long-lived, so decisions made today about their maintenance, renewal and enhancement will shape the resilience of the network for decades.
The objective should therefore be twofold. Firstly, to reduce physical vulnerability where intervention is justified, and secondly to plan more effectively for the conditions in which restrictions will still be necessary. Greater use of forecasts, known vulnerabilities and pre-planned extreme-weather timetables could help determine in advance what service can realistically be operated, providing passengers and freight customers with greater certainty when the normal timetable cannot be delivered.
For a railway that will continue to rely heavily on its existing infrastructure, adaptation will be gradual and cumulative. It will be built through thousands of decisions about where to maintain, monitor or renew assets, how to operate when conditions deteriorate and what is learned from each event. Bringing those decisions together will be fundamental to maintaining a safe, reliable and resilient railway as the climate changes.
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