Londoners are not imagining things when they complain of suffering more than most during heatwaves. The capital really does experience higher temperatures than many other areas of the country.
London is located in the warmest part of Britain, the south-east, well away from the weather fronts that usually arrive from the Atlantic and travel eastwards.
But the biggest factor is known as the urban heat island effect. Most city areas have lots of dark, man-made surfaces – like concrete – which absorb the Sun’s energy instead of reflecting it.
Together this means that London is often the hottest place in the UK, and several degrees warmer than surrounding rural areas.
See also: Why the capital's infrastructure is not made for a heatwave
It’s not news to anyone that London is not well-adapted to hot weather. Many of our offices and homes are poorly ventilated and can overheat even on relatively cool summer days.
Overheating buildings mean workers are less productive. But it’s also medically dangerous – being a threat to people living with underlying health conditions, such as respiratory illnesses. Indeed, hundreds of Londoners die every summer due to heatwaves.
Although many larger buildings now have air conditioning, the effect of this is simply to transfer heat from indoors – exacerbating the problem outdoors.
This issue is getting worse due to climate change, which is making heatwaves both more frequent and more intense.
And they will become more common and severe for at least the next 25 years until the world reaches net zero emissions of greenhouse gases.
So, clearly, Londoners need to become more resilient to the heat. We need to learn good habits from places that are used to higher temperatures. One simple measure is keeping windows and blinds shut during the middle of the day, instead of opening them up and letting in hot air from the outside.
Other steps we should take include attaching shutters to the outside of our windows and painting buildings white to reflect the Sun’s energy, like in Mediterranean countries.
We also need more trees and vegetation that absorb the Sun’s energy and provide shade.
If London fails to do this, it will cost us growing numbers of lives and livelihoods.
The Mayor must make resilience to heat and the other impacts of climate change a priority for his new London Plan. The Plan should make sure that all new and existing buildings are better suited to deal with the heat, and it should stop developments on green belt land that increase the urban heat island effect.
Bob Ward is Chair of the London Climate Ready Partnership
