Heat Ready London - London’s first ever heat plan - sets out new vision to protect the capital from extreme heat - as temperatures soar in the capital

Heat Ready London - London’s first ever heat plan - sets out new vision to protect the capital from extreme heat - as temperatures soar in the capital 

• New Heat Ready London vision focuses on priority areas where change is most needed, calling for the protection of those at highest risk of extreme heat, retrofitting of buildings, expanded access to cooling spaces and improved infrastructure resilience.
• Analysis reveals one million London homes may be at high risk of overheating, with more than 1,300 schools, 60 hospitals and 351 care homes located in high heat risk areas.
• London experienced an all-time May record temperature of 35.1C this year, following summer 2022 heatwaves, where temperatures exceeded 40°C and cost an estimated £1.5 billion.
• Mayor launches new city-wide vision during London Climate Action Week, the capital’s first ever heat plan and one of the first in the country, calling on partners to protect lives and strengthen the resilience of the capital to rising temperatures and extreme heat.

The Mayor of London, Sadiq Khan has today unveiled the capitals first ever heat plan - Heat Ready London – a new city-wide vision to help the capital adapt to increasingly frequent and severe heatwaves. It comes as temperatures in London this week could reach 40 degrees and the Met Office have issued a rare red alert for extreme heat in the capital.

London as a city is more exposed to heat risk than anywhere else in the UK and earlier this year, the capital experienced a new all-time May record temperature of 35.1C.

The need for action is becoming increasingly urgent as London experiences more frequent and severe heatwaves. The UK experienced one of its hottest and driest summers on record in 2018, before temperatures reached a then record high of 38.7°C in 2019. In 2022, temperatures exceeded 40°C for the first time in UK history and the Met Office issued its first ever Red Extreme Heat Warning. This week's forecast temperatures are also record-breaking for June and have triggered only the second Red Heat-Health Alert since the system was introduced in 2003. Experts warn that this prolonged period of extreme heat, combined with very high overnight temperatures and humidity, could have even greater health impacts than the July 2022 heatwave. Scientists expect extreme heat events to become more frequent and intense as the climate changes, underlining the need to prepare the capital for a hotter future.

Setting out the scale of the challenge, the Heat Ready London report shows that around 1 million homes in London may currently be at high risk of overheating. A further 1,361 schools, 60 hospitals and 351 care homes are located in high-risk areas across the city, while London could face between two and three times as many heatwaves as it currently experiences within 20 years.

A new study produced to support the development of Heat Ready London found that London's 2022 heatwaves are estimated to have cost the city £1.5 billion, reflecting the combined impact on health, learning, transport, energy use, emergency services, wildfires and lost productivity. [1] This also put unprecedented strain on public services, including the London Fire Brigade, who experienced their busiest day since the Second World War. [2]

There are nearly 4,000 additional hospital attendances during hot weather in London during the summer, in addition to an estimated 300 additional, preventable deaths each year in the capital. UK-wide heat-related hospital attendances and admissions could triple by 2050 compared to current levels. These impacts are disproportionately concentrated in London.

In 2025, London also experienced its highest number of wildfires since the extreme heat of 2022. Firefighters attended around 88 wildfires across the capital during June, July and August, with 122 wildfire incidents recorded by the end of August. This is double the number seen in 2023 and a 42 per cent increase on 2024. This trend highlights the growing risk from hot and dry conditions. [3]

The Mayor is already tackling overheating through the London Plan, which requires new homes to be designed to stay cooler in hot weather using measures such as shading, ventilation and smarter design, helping to reduce the need for energy-intensive cooling. The Mayor also recognises that addressing overheating in much of London's existing housing is a key priority and will require coordinated action across government, councils and the housing sector to keep Londoners safe and comfortable as temperatures rise.

The Heat Ready London report, which the Mayor unveiled during London Climate Action Week (LCAW) this week, provides a new city-wide vision that sets out how London needs to work together to adapt the capital to a hotter climate.

Heat Ready London is a call to action for partners across the capital, providing a framework to drive collective action, protect lives, strengthen resilience and ensure London remains a place where everyone can thrive.

It will help shape how cities across the UK respond to rising temperatures and adapt to a warming climate by identifying where action is most urgently needed. The report builds on previous work led by the Mayor, including the London Climate Resilience Review, which was commissioned in 2023, and Exercise Helios in 2024, which tested London's response to extreme heat. [4]

Heat Ready London focuses on six key sectors: the built environment, business and economy, emergency preparedness, resilience and response, health and care, green space and nature and infrastructure.

Heat Ready London sets out five objectives for a heat-resilient London:

1.         Protect Londoners from the health impacts of high temperatures

2.         Reduce inequalities by prioritising those most at risk

3.         Ensure buildings, public realm, and green spaces are adapted to heat and provide shade

4.         Maintain essential services and infrastructure; and

5.         Support productivity and economic resilience.

Recognising that no single organisation can address the scale of the challenge alone, the report sets out 37 priority areas of focus, highlighting where change is most needed in the short, medium and long-term. This includes:

• Expanding access to cooling spaces and public drinking water to deliver well-maintained water points to support hydration and cool outdoor spaces during heat events.

• Retrofitting the highest risk homes to reduce the risk of indoor overheating to protect the most vulnerable, particularly in high-risk areas.

• Increasing urban greening, which will include providing more tree cover and green spaces in priority areas, providing long term cooling and shade.

• Expanding safe access to blue spaces, such as swimming and other recreation based around London's waterways, that provide opportunities for residents to cool down.

• Strengthening health and care system resilience, which will ensure a more coordinated and integrated communications effort during heat incidents.

• Improving the resilience of critical infrastructure, which includes making London's transport infrastructure as reliable and safe as operationally feasible in high temperatures.

Transport for London (TfL) is continuing to adapt the capital's transport network to more frequent and severe heatwaves. More than 190 Tube trains, covering around 40 per cent of the Underground network, are now air-conditioned, alongside all London Overground and Elizabeth line trains, with new air-conditioned Piccadilly line and DLR trains set to further improve passenger comfort. TfL is also investing in station cooling and ventilation measures, while all new double-decker buses are fitted with air cooling. Water refill points at stations also help Londoners stay hydrated during periods of extreme heat.

The Mayor has emphasised that adapting to hotter temperatures is also a matter of social justice. People living in poorly designed homes, those without access to green space, older people, young children and those with physical or mental health conditions are often most vulnerable to heatwaves and its impacts.

The Mayor is working closely with partners to ensure vulnerable people and those most at risk are protected, including local councils providing emergency support to rough sleepers. There are 4,000 free water refill points and more than 100 water fountains across our city to stay hydrated and cool spaces across the capital where you can take a break and cool down. [5] The Mayor has also funded the planting of more than 640,000 trees since 2016, for shade and cover.

Mayor of London, Sadiq Khan, said: “Rising temperatures are no longer a future threat - they are becoming a growing reality for Londoners. It is affecting our communities, from homes and high streets to schools, hospitals and care services. 

“That is why I am proud to unveil Heat Ready London, London’s first ever heat plan. This is a new vision that will help tackle the huge obstacles we face with rising temperatures.

“No single organisation can address the scale of the challenge alone, so this is a call to action to our partners to use this framework to drive collective delivery so we can protect lives and strengthen the resilience of our city.

“We must act now. By working in partnership, we can ensure the benefits of climate action are shared by all Londoners and that those who are most vulnerable are protected as we build a greener and fairer London for everyone.” 

Steps are already underway to ensure the effective delivery of Heat Ready London and strengthen cross sector collaboration to align priorities, pool resources and deliver interventions at scale.

Earlier this month, Deputy Mayor of London for Environment Mete Coban convened a roundtable with partners to agree priorities and identify where coordinated action can have the greatest impact. This roundtable marked the starting point of this next phase, including helping shape the governance and partnership arrangements.

Deputy Mayor of London for Environment, Mete Coban, said: “Hotter temperatures are becoming a growing reality in London.

“That’s why the Mayor, in partnership with London Councils, has developed Heat Ready London, setting a new benchmark for how cities across the UK can respond to heat risk and adapt to a warming climate.

“This is a matter of social justice - because high temperatures do not affect everyone equally. People living in poorly designed homes, people without access to green space and people with underlying health issues are hit hardest.

“The effective delivery of this work will depend on strong collaboration across sectors so Sadiq and I will continue to work closely with partners to ensure Heat Ready London is targeted, evidence-led, and responsive to inequality, while continuing to reflect the experiences of Londoners.”

Professor Emma Howard Boyd CBE, Chair, National Heat Risk Commission and former Chair of the London Climate Resilience Review said: “Extreme heat is already one of the most significant and rapidly escalating risks facing London, and with the temperatures we have seen this week, the urgency to act could not be clearer. I welcome the Mayor's leadership in responding to it.

“Heat Ready London turns the recommendations of the London Climate Resilience Review into a clear programme of action to protect communities and prepare the capital for a hotter future. Cooling our city — through trees, parks, shaded streets and cooler buildings — does more than bring temperatures down: it cleans our air, reduces flood risk and makes neighbourhoods better places to live.

“But extreme heat already hits hardest in the most deprived communities, and during periods of intense heat this inequality becomes even more dangerous. These benefits must be delivered quickly and fairly, with shade, green space and practical support targeted to where they are needed most — ensuring every Londoner can stay safe, cool and well in a changing climate.” 

The London Fire Commissioner, Jonathan Smith, said: “Extreme heat is no longer an occasional challenge, it’s becoming an increasingly regular risk for London, as demonstrated just this week. Responding to this challenge requires a joint effort from the public and organisations across London, including taking steps to in advance to prevent or minimise the harm and damage caused. 

 “We’ve learnt from previous events, such as the summer of 2022, and invested in new equipment and training to help tackle wildfires and we will continue to improve our capability so that we are ready and prepared for future summers, as the threat from wildfires continues to increase. 

“Heat Ready London recognises that adapting to a hotter climate requires a coordinated effort across all sectors. By working together to improve resilience and better protect those most at risk, we can help prevent emergencies before they happen and ensure London is better prepared for future heatwaves.” 

Lilli Matson, Chief Safety, Health and Environment Officer at TfL, said: “This report highlights the increasing risks that extreme heat poses across London, including to critical infrastructure such as transport. The ongoing heatwave has underlined the importance of preparing for such conditions and their real-world impact on customers, staff and the transport network. We are working with other agencies, including Network Rail, the Greater London Authority and others to develop a coordinated approach and manage the adverse impact of higher temperatures on our network, from track and road surface resilience to customer comfort and staff safety.

“We are taking action to strengthen our resilience, including investing in cooling and ventilation, and adapting our infrastructure and operational responses. For example, every bus has a reflective roof and opening windows, while all new double-decker vehicles have air-cooling capability. 192 air-conditioned Tube trains cover 40 per cent of the network, and every Elizabeth line and London Overground train is air conditioned. Approximately a third of TfL’s estate is covered by vegetation that helps keep London cool, and almost 25,000 street trees provide shade.

As climate change continues to drive more frequent and intense heatwaves, we remain committed to ensuring the capital’s transport network can operate safely and reliably, while helping London become a more climate-resilient city.”

Cllr Paul Osborn, London Councils’ Executive Member for Transport and Environment, said: “Boroughs have a crucial role to play in protecting residents from extreme heat - keeping homes, buildings and streets cooler as temperatures rise, while making sure the most vulnerable Londoners are shielded from its worst effects. 

"Heat Ready London marks a vital step in responding to the hotter summers we now face in London, and we will be actively working with the Greater London Authority and partners across the capital to turn that ambition into coordinated action that keeps our communities safe."  

Dr Tom Coffey OBE, Mayoral Health Adviser and London GP: “Heat is no longer a distant concern. It is now the greatest risk to health from climate-change in the UK, and we are already seeing its impact here in London, including record temperatures, early heat alerts and rising heat-related deaths. 

“As a GP, I see first-hand that heat doesn’t just affect those we traditionally think of as vulnerable, such as those with mental and physical health conditions - it can impact any of us. That's why Heat Ready London is so important, as it sets out clear actions to support Londoners, such as embedding heat risk in care pathways and driving the partnerships needed to meet this challenge together. 

“In London we are reaching a tipping point and the time to come together is now - with health services, local government, communities and partners all working together to build a coordinated response to protect Londoners.” 

Dr Alan Dangour, Director of Climate & Health at Wellcome, said: “Climate change is driving hotter summers and more frequent heatwaves, and London is more exposed to heat risk than anywhere else in the UK. Without action, the health impacts of climate change will only intensify - with groups like pregnant women, outdoor workers and older people most at risk. The Mayor’s vision - from public health guidance to preventative measures - provides an essential framework for the whole of society to act together to save lives and keep Londoners safe.”