United Kingdom 2022
Drought and Heatwave in summer 2022The UK summer of 2022 was characterised by extremely hot and dry conditions leading to severe drought and five heatwave periods. Between 18th to 19th July, an unprecedented extreme heatwave affected the UK, setting new maximum temperature records across the UK and Ireland with temperatures of 40 °C recorded for the first-time.
The extreme temperatures resulted in roads and airport runways melting and railways buckling, which caused widespread disruption across the transport network. In our study, we have chosen to investigate the temporary closure of Luton Airport, located in Bedfordshire, on 18th July when part of its runway melted in the extreme heat. Little research exists surrounding the impact of climate change on airports, so we aim to increase awareness to improve long-term resilience.
The 2022 drought-heatwave caused excess deaths, widespread transport disruption, wildfires, power cuts, agricultural losses, and the temporary closure of Luton Airport, where runway melting led to major flight cancellations, diversions and significant operational challenges across interconnected infrastructure systems.
Geographical context
The July 2022 drought-heatwave unfolded across much of the UK, with the most severe impacts concentrated in southern and eastern England. This region is characterised by densely populated urban centres, major transport corridors, and critical infrastructure nodes including airports, railways, and motorways. Luton Airport, located in Bedfordshire to the north of London, sits within one of the UK’s busiest travel corridors and serves as a major hub for domestic and international passengers. Its elevated position and surrounding landscape of mixed urban and semi-rural areas exposes it directly to the extreme temperatures. In summer 2022, Luton Airport saw 10 days exceed the county’s heatwave threshold of 28°C. On 18th July, the day the runway melted, a new surface temperature record of 56.9°C was observed alongside an air temperature of 35.9°C. The following day, a new local maximum air temperature of 38.6°C was recorded, reflecting the intensity and persistence of the heat.
Timeseries of Luton Airport maximum daily air temperature for 2022 (black line), overlaid on annual cycles from 2001 to 2024 (grey lines). 10 days in the summer exceeded the county’s heatwave threshold of 28 °C. Data courtesy of Vaisala.Nearby regions—including Hertfordshire, Cambridgeshire, and Greater London—also experienced prolonged dryness, depleted soil moisture, and record-breaking temperatures. This combination of meteorological conditions and regional vulnerabilities made southern and eastern England the epicentre of the drought-heatwave’s most acute impacts.
Historical context
Over recent decades, the UK has undergone significant demographic and infrastructural change, particularly in southeast England, where population growth and urban expansion have increased pressure on transport networks. Luton Airport has grown substantially since its opening in 1938, reflecting broader trends in low-cost aviation and increased international mobility. Passenger numbers have risen sharply, with the airport becoming one of the UK’s fastest-growing terminals prior to the COVID-19 pandemic. The region’s economic development has coincided with increasing exposure to climate-related risks: rising temperatures, growing water stress, and repeated summer heatwaves. England experienced major heat and drought events in 1976, 2003, 2018, and again in 2022, each influencing public awareness, land management, and infrastructure performance. These historical developments shaped the context in which the 2022 drought-heatwave produced such widespread and cascading impacts.
COMPOUND HAZARd
The drought–heatwave event of summer 2022
The drought–heatwave event of summer 2022 was a landmark moment for the UK, marked by record-breaking temperatures and a rare combination of compounding and preconditioning hazards. On 19th July, the country experienced its highest temperature ever recorded—40.3°C at Coningsby, Lincolnshire—surpassing the previous national record by 1.6°C. This extreme heat did not develop in isolation. In the months preceding the event, the UK, and particularly eastern and southern England, faced unusually dry and sunny conditions. From January to August, only 62% of the average rainfall was recorded, resulting in a deficit of 183 mm compared with the 1991–2020 baseline. Sunshine levels were similarly exceptional, with southern and eastern England experiencing their sunniest January on record, and March recording 152% of the UK average. These conditions helped create a multivariate hazard environment where drought and heatwaves overlapped, heightening risks for multiple sectors including agriculture and wildfire management. Evidence from previous UK heatwaves in 2003 and 2018 shows that low soil moisture significantly amplifies maximum temperatures during extreme events, and 2022 followed this pattern.
Maximum temperatures recorded on 18th July (left) and 19th July (right) 2022. The right image shows the 46 climate stations across England that equaled or exceeded the previous UK record of 38.7 °C. Figures from Kendon et al. (2023).
UK rainfall (left) July and (right) January-August 2022 anomalies relative to 1991-2020 average. Figure provided by Kendon et al. (2023).
The meteorological setup driving the July event involved a stationary high-pressure system over continental Europe, which sustained a southerly airflow drawing very hot, dry air from northern Africa into the UK. Mass subsidence contributed to the formation of a heat dome, trapping warm air close to the surface and enabling temperatures to rise to unprecedented levels. A mix of global and regional weather patterns drove the development of the extreme heatwave. Warm ocean conditions in the Pacific helped set up large waves in the atmosphere that encouraged high-pressure conditions to develop. At the same time, summer weather patterns over the North Atlantic shifted storms further north than usual, leaving the UK drier and hotter. Unusually warm waters in the Gulf Stream also added extra energy to the atmosphere, helping reinforce the stable, hot conditions over western Europe. Local factors further intensified the event—sunshine-driven evaporation depleted soil moisture, reducing cooling, while record-breaking regional sea surface temperatures above 20°C in southern and eastern England may have increased temperatures through the advection of warm marine air.
Visible satellite image on 19th July 2022 showing cloud-free skies across central and eastern England in a hot dry airmass. Image copyright Met Office / NOAA / NASA.
Observed impacts
The July 2022 drought-heatwave triggered widespread and compounding impacts across the UK
The July 2022 drought-heatwave triggered widespread and compounding impacts across the UK, intensifying over several weeks as extreme temperatures combined with prolonged dryness.
Between 10 and 25th July, the UK recorded 2,227 excess deaths, with the greatest number on 19th July when temperatures peaked nationally. Central and southern England suffered the most severe consequences for health, infrastructure and the environment. Wildfires broke out across multiple counties, leading several fire services to declare major incidents as crews faced unprecedented pressure and stretched capacity. Transport networks experienced significant disruption: roads softened or melted, rails buckled, and power supply risks forced widespread train cancellations. Passengers faced delays, overcrowding and poor ventilation on services that remained operational, with essential workers and those needing to travel for medical reasons particularly affected. Social care workers also dealt with increased pressure as vulnerable individuals required additional monitoring, while transport disruption and school closures contributed to staffing shortages, fatigue and stress.
Within this national picture, one of the most visible infrastructure failures occurred at Luton Airport when its runway melted on 18th July. This forced the temporary closure of the airport and led to the diversion of 13 flights to other London airports and the cancellation of 100 flights. This disrupted thousands of passengers and placed considerable strain on terminal staff and airline operations.
For the agricultural sector, the impacts extended far beyond the peak heatwave period. The prolonged drought from late spring to mid-autumn reduced crop yields, affected livestock productivity, and increased energy and water demand. These cumulative stresses have taken a toll on mental health, with a 2024 survey reporting that 95% of farmers under 40 believe climate change has negatively affected their wellbeing.
Overall, the 2022 drought-heatwave evolved into a multi-sector crisis in which extreme temperatures initiated a cascade of health, infrastructure and economic impacts. The runway failure at Luton Airport became a striking symbol of the UK’s vulnerability to compound climate extremes and the operational, social, and economic disruptions they can unleash.
Impact summary
2,227 excess deaths due to heat between 10-25th July
13 deaths due to open water swimming (between 8th-19th July)
500% increase in fire 999 calls during heatwave peak (13,500 on 19th July)
14 fire and rescue services declared major incidents as they tackled 983 wildfires in summer 2022 (84 on 19thJuly)
Passenger train numbers were 40% lower between 18-19th July compared to the previous week
A ‘Do not travel’ warning was issued by Network Rail
Closure of East Coast Main Line on 19th July and partial closure on 20th due to overhead cable fire
Roads in Cambridgeshire, Oxfordshire and Lincolnshire were closed
Luton Airport and RAF Brize Norton temporarily closed due to melting runway, delaying and diverting flights
9.2% reduction in chicken meat production
18,500 chickens died in transport due to heat stress (July-August)
8% higher wheat yields than 2017-2021 average
6 water companies issued Temporary User Bans affecting at least 19 million people
An extra 300 million litres of water a day was being used during the peak of the heatwave
41 properties destroyed in London due to wildfires
8000 properties in Yorkshire, Lincolnshire and the Northeast experienced power cuts
Wildfires destroyed habitats of nesting birds, reptiles and amphibians
Marked decline in insect populations e.g. dragonflies, butterflies
Response
The response to the July 2022 drought-heatwave unfolded rapidly as extreme temperatures created widespread and compound impacts across the UK. As conditions intensified and forecast guidance indicated life-threatening heat, the Met Office issued its first-ever red warning for extreme heat. This unprecedented alert marked a critical moment in the UK’s hazard response system and signalled that exceptional measures were required to protect public safety. At the same time, the UK Health Security Agency escalated its heat alert to Level 4, the highest level, indicating a national emergency with potential for significant health and infrastructure disruption. These warnings triggered immediate public communication campaigns, activated emergency service preparedness, and prompted hospitals, care homes and local authorities to implement heat-response actions to safeguard vulnerable groups.
Operational responses during the event revealed the strain placed on frontline services. Fire and rescue teams, already stretched by widespread wildfires, reported that resources were pushed to their limits. Health and social care workers faced rising demand as they monitored high-risk patients while navigating disruptions to transport and staffing. Transport operators responded by slowing or cancelling services to reduce safety risks from buckling rails, damaged road surfaces and overheated power systems, though these actions created significant challenges for passengers and workers needing essential travel. At Luton Airport, where the runway failed under extreme temperatures, staff were required to manage diverted flights, cancellations and stranded passengers with limited operational flexibility, highlighting the difficulty of responding to rapid-onset infrastructure failure during extreme heat.
Operational responses during the event revealed the strain placed on frontline services. Fire and rescue teams, already stretched by widespread wildfires, reported that resources were pushed to their limits. Health and social care workers faced rising demand as they monitored high-risk patients while navigating disruptions to transport and staffing. Transport operators responded by slowing or cancelling services to reduce safety risks from buckling rails, damaged road surfaces and overheated power systems, though these actions created significant challenges for passengers and workers needing essential travel. At Luton Airport, where the runway failed under extreme temperatures, staff were required to manage diverted flights, cancellations and stranded passengers with limited operational flexibility, highlighting the difficulty of responding to rapid-onset infrastructure failure during extreme heat.
In the weeks and months after the heatwave, the scale of disruption prompted reflection on the adequacy of existing systems. Recognising the need for clearer, more impact-based communication, the government introduced the Adverse Weather and Health Plan (AWHP) in April 2023. Central to this was a new Weather-Health Alerting System designed to provide more targeted warnings of extreme heat and cold and improve preparedness across health and emergency services.
Extent of Met Office red extreme heat warning issued for 18th to 19th July. Source: Kendon (2022) https://www.weather.gov/media/rnk/Newsletter/22FA-2022_UK_july_heatwave.pdf
The system has since been activated multiple times during subsequent heat events, signalling a shift toward earlier and more proactive hazard communication. Alongside this, extreme heat guidance was updated through the release of the third National Adaptation Programme (NAP3), which sought to strengthen understanding of temperature-related risks and support organisations in preparing for future events. These developments represented early efforts to adjust systems following lessons learned from 2022.
Despite these developments, recent assessments of guidance for extreme cold and hot weather shows a predominant focus on health impacts, with far less attention for transport, education and agriculture. The 2022 heatwave therefore marked a pivotal moment, highlighting the need for cross-sector resilience - revealing both the capacity of UK institutions to mobilise during extreme events and the substantial operational challenges that arise when multiple hazards converge across critical systems. The event underscored how quickly extreme heat can overwhelm response mechanisms and highlighted areas where further preparedness work will be required.
Attribution analysis
To understand how human-caused climate change influenced the 2022 drought and heatwave, we compare two versions of the event. The factual version shows what happened in today’s warmed climate, while the counterfactual version shows how the same event might have unfolded in a world without human-caused warming, as well as scenarios with different exposure and vulnerability. Comparing these scenarios helps us see how much climate change increased the likelihood or severity of the impacts.
For the runway melting analysis, we first identify an impact threshold. We found that the average air temperature in the six hours before the hottest daily temperature best predicts extreme runway temperatures. Because the runway has melted only once (on 18th July 2022), we use the six-hour air temperature before that event as our benchmark. The runway reached 56.9°C, and the six-hour average air temperature of the period from 7.30AM - 13.30PM from that day exceeding the threshold defines a “runway-melting event.”
Attribution analysis workflow
To assess how the event looked in 2022 compared to a world without climate change we use HadGEM3-A climate simulations—525 run in the present climate and 525 run in a counterfactual climate each with similar SST patterns to 2022. We then looked at how likely it is for the model runs to exceed the impact threshold in each climate. In addition to the climate, we also assess how exposure and vulnerability have changed. Luton Airport now handles far more passengers and flights than in 1980, increasing exposure. Vulnerability is evaluated using existing studies on infrastructure sensitivity and dependence on external systems.
Probability density curves showing the likelihood of exceeding the impact threshold (black line) in the 2022 climate (pink) and a pre-industrial climate (green)
Attribution results
To quantify the influence of anthropogenic climate change on the runway melting, we compared the probability of exceeding the impact threshold—defined as a six-hour average air temperature of 29.5°C between 07:30 AM and 13:30 AM—in both a factual (current) and counterfactual (pre-industrial) climate. The results show that climate change increased the chance of exceeding this threshold by 12 times, with uncertainty bounds indicating that it was at least six times more likely and potentially up to 32 times more likely. The analysis indicates that the event would be extremely rare in a counterfactual climate, occurring only once every 175 years, whereas in today’s climate the return period is approximately 15 years under similar conditions to 2022.
The intensity of heat associated with a 15-year return period also differs substantially between the two scenarios. A 1-in-15-year event in the counterfactual world would be about 2.1°C cooler for the impact threshold (confidence interval 1.8–2.3°C) than in the present-day climate. This means that there is high confidence that an event with the same return time in the counterfactual climate would have resulted in no impacts. Consistent with other studies, we also find that extremely low soil moisture during the 2022 drought strongly amplified 6-hourly temperatures, highlighting the importance of preconditioning and the combined effect of drought and heat. These findings are consistent with other attribution studies of the 2022 heatwave, which also show strong climate-change signals across impacts such as heat mortality, wildfires, and record-breaking temperatures.
Alongside changes in climate hazard, shifts in airport activity have significantly increased exposure to such events. Comparing airport usage in 1980 with 2022 shows that higher passenger numbers and flight volumes today greatly magnify the impacts of extreme heat. If a 2022-type melting event had occurred in 1980, approximately 58 flights and 2,116 passengers would have been affected. In reality, the 2022 event disrupted 113 flights and an estimated 13,000 passengers, representing a 93% increase in flight disruptions and a 531% increase in impacted passengers. With Luton Airport planning to almost double its annual passenger numbers by 2043, a runway-melting event similar to 2022 could disrupt around 275 flights and more than 32,000 passengers, assuming the same proportion of flights and passengers are affected as in 2022. This illustrates how growing airport usage could significantly amplify the consequences of extreme heat events.
Disrupted flights for similar heat events in Luton compared between factual and counterfactual exposure levels.
Number of passengers affected by flight cancellations for similar heat events in Luton compared between factual and counterfactual exposure levels.
The vulnerability of Luton Airport is also closely tied to the characteristics of its infrastructure. Its rigid, concrete runway—designed to carry heavy aircraft—cannot expand under extreme heat, unlike the more flexible asphalt runways used at other major London airports. This structural difference is a key reason Luton was uniquely affected during the 2022 heatwave. The airport also depends heavily on surrounding infrastructure such as roads, railways, and pedestrian routes, which are themselves vulnerable to heat-related damage. Failures in these networks can cascade into further delays, cancellations, and disruptions to other services such as hotels and car rentals.
Policy implications
The analysis of impacts, responses, and the role of climate change highlights several critical entry points for policy action to minimise future disruption. The 2022 drought-heatwave raised critical concerns over the preparedness and resilience of the UK's transport infrastructure in the context of a changing climate. Our findings demonstrate that anthropogenic climate change significantly increased the likelihood and intensity of the extreme temperatures observed in summer 2022, alongside an increase in their frequency under current climatic conditions. Our study reveals the amplifying role of socio-economic factors, particularly increased airport exposure, in determining the severity of impacts associated with such extreme events. This is of particular relevance to Luton Airport as it begins a period of major expansion. Without the implementation of adaptation and resilience measures, this growth will only enhance the airport's vulnerability to climate-related hazards. As such, future development must be climate-focused to ensure long-term operational resilience.
Although flight diversions helped manage the 2022 runway melting incident at Luton, future heatwaves could affect several airports at once, creating far greater national-level socio-economic impacts. This possibility calls for coordinated national contingency planning across the aviation sector, including shared diversion strategies, consistent heat-resilience protocols, and joint preparedness exercises. Strengthening resilience requires a system-wide approach: Luton Airport relies heavily on external infrastructure—roads, railways, and pedestrian routes—that are themselves vulnerable to extreme heat, with surfaces melting, rails buckling, and transport services failing. Disruptions in these networks can quickly cascade into airport delays, cancellations, and wider commercial losses. These interconnected risks demonstrate the need for integrated planning between airport operators, local authorities, highway agencies, and rail operators to ensure that heat resilience is addressed across the transport system as a whole rather than at individual sites.
Several other policy measures emerge from these findings. First, there is a need to reconsider engineering and construction standards—especially runway material specifications—to ensure they remain fit for purpose under projected temperature extremes. Second, airport operators could use the six-hour temperature impact threshold identified in this analysis to establish operational heat triggers and early warning protocols. Third, regulatory bodies such as the Civil Aviation Authority (CAA) and the Department for Transport (DfT) may need to incorporate climate attribution evidence into planning approvals, safety guidance and long-term risk assessments. Finally, economic planning should account for avoided losses: strengthening runways and associated infrastructure may offer substantial cost savings compared to future disruption under increased passenger demand.