London is at “extreme” risk of wildfires as it frazzles in its third heatwave of the year, civic chiefs are warning.
Sir Sadiq Khan took an unprecedented step this week in urging Londoners to create firebreaks to protect their homes.
The Mayor of London issued the alarming alert after a blaze swept through 30 gardens and damaged properties in Walthamstow, in the east of the capital, on Sunday.
The wildfire threat differs significantly across London.
Experts at geospatial analytics company Map Impact analysed the risks in every borough in the city.
The wildfire danger is greatest in Havering, in the far east of the capital and the only borough which stretches across the M25, according to their research.
Just over 11% of its land is assessed to be at high or very high risk of wildfire.
The second highest risk borough is in the west of the capital, Hounslow, at just under 10%.
If a major blaze spread in this local authority it could impact on Heathrow airport in the neighbouring borough of Hillingdon.
The likelihood of wildfires is higher in Outer London boroughs where there are far more green spaces than in the city centre.
The risk also depends on how many people visit areas as the higher the number the more likely it is that a blaze could be accidentally sparked.
Wildfires can be caused by sunlight on a glass bottle, or a piece of glass, igniting a parched area, by a dropped cigarette butt, a BBQ, or sparks from machinery or vehicles.
Richard Flemmings, chief executive of Map Impact, told The Standard: “The combination of hot temperatures, very dry vegetation and strengthening winds creates the conditions in which small fires can spread rapidly and become much harder to control.
“Our WildfireView data shows that the highest susceptibility remains concentrated around London's outer boroughs and urban fringe, where large areas of grassland, scrub and open space sit alongside homes and infrastructure.”
Mr Flemmings explained further: "While individual wildfires are triggered by an ignition source, the broader trend is clear.
“Climate change is increasing the frequency of the hot, dry weather patterns that elevate wildfire risk across the UK.
“Conditions that were once considered exceptional are becoming more common, extending the wildfire season and increasing the exposure of communities, businesses and public services.”
The third highest risk borough is Ealing.
Just over nine per cent of the borough is at high or very high risk of wildfires.
Barking & Dagenham is next, at 8.69%, followed by Bexley 8.21%, Redbridge 7.14%, Richmond-upon-Thames 6.28%, Hillingdon 6.23%, Enfield, 6%, Merton 5.81%, Harrow5.54%, Haringey 5.08% and Brent 5.04%.
At around half the wildfire risk as the boroughs with the highest dangers is Sutton and Greenwich, both on 4.84%.
They are followed by Newham on 4.52%, Kensington & Chelsea 4.25%, Bromley 4.07%, Lambeth 3.56%, Croydon 3.55%, and Westminster3.54%.
Some Inner London boroughs, such as Westminster, will have higher risk ratings than may have been expected and this is partly due to Royal Parks, including around Buckingham Palace, which can be tinderboxes in theses arid conditions.
Waltham Forest, which includes Walthamstow, has around a third of the wildfire risk of Havering and Hounslow, at 3.48%, followed by Lewisham on 3.36%, and Barnet 3.14%.
Boroughs will less than 2% of their land at high or very high risk of wildfire include Hammersmith & Fulhamat 1.98%, Southwark 1.97%, Wandsworth 1.77%, Hackney 1.72%, Kingston-upon-Thames 1.4%, and Camden 1.15%.
The lowest risk local authority areas are Islington at 0.86%, City of London0.2% and Tower Hamlets at just 0.17%.
The London Fire Brigade (LFB) has issued guidance in the face of the threat of wildfires, including advising people to clear two to three metre strips around their garden to create firebreaks.
LFB Assistant Commissioner Tom Goodall said: “As these very warm and dry conditions continue, we encourage all landowners, including households, to take any precautionary measures they can to protect properties in the event of a fire.
“Residents can also help minimise damage by keeping grass cut low and cutting back trees and shrubbery, particularly around the edges.”
London has been hit by record temperatures in the three heatwaves so far this year, with the first two, in May and June, estimated to have killed 1,000 people in the capital and wider South East.
Amid the worrying pace of global warming, the number of 30C days in the city has quadrupled in the ten years to 2025, compared to previous decades.
