Threat of France-style wildfires 'on our doorstep,' warns Sadiq Khan as London faces 'exceptional' risk this week

Sir Sadiq Khan has warned of the risk of wildfires similar to those raging in France bearing down on London as it faces an “exceptional” threat from blazes this week.The London Mayor sounded the alarm over the growing danger of wildfires due to weeks of almost no rain, parched land, rising temperatures and less humidity.The “perfect storm” of wildfire conditions means the capital faces an “exceptional” risk of blazes spreading on Wednesday.A spokesperson for the Mayor of London said: “The climate crisis is having a devastating impact on our environment with temperatures rising to record levels in London and around the world so far this summer. A firefighter stands before flames as a forest fire rages in Saint-Jean-d'Illac, some 20 miles from BordeauxAFP/Getty“This isn’t a faraway issue, it's on our doorstep right now.”The upgraded warning is based on significant impacts being “likely” across health and social care services, including a rise in deaths, particularly among those aged 65 and over or with health conditions, and other sectors such as transport possibly being affected. The capital is forecast to swelter in 28C on Monday, 29C on Tuesday, a peak of 33C on Wednesday, before falling to 28C on Thursday and then cooling slightly.Read MoreIn guidance for people who discover a wildfire, the LFB stressed:* Make sure you're in a safe place (away from vegetation and smoke)* Stay calm and call 999 immediately* If you're in your car, close all windows and vents* When you call 999 be as precise as you can about the location, the blaze size and any other information * The free what3words app can help you pinpoint your location, so download it now* Don't try to tackle the fire yourself * Stay well away from wildfires as fire can smoulder or spread undergroundA major blaze destroyed and damaged homes in WalthamstowLondon StandardLondoners are being urged not to use BBQs in parks, to make sure cigarette butts are properly extinguished, and not to leave glass, or fragments of glass, lying around as this can lead to fires ignited by sunlight.If they start, fires are likely to become “exceptionally severe” on Wednesday in parts of London, the South East, and East, according to Met Office data used by Natural England and Natural Resources Wales.This threat remains in areas of the South East and East on Thursday.Met Office senior operational meteorologist Dan Stroud said: “In terms of wildfire, obviously the continuation of the dry and hot conditions does elevate the fire risk.“That rain we’ve had, even though it’s welcome rain...is certainly not enough really to do a huge amount for the dry conditions we’ve already already got.”The Fire Severity Index looks at data including rainfall, temperature and humidity.Mr Stroud explained that drier weather, with less humidity, increases the fire spread risk.Buckingham Palace wildfire threat as assessed by Map Impact expertsPA/GettyThe second heatwave was particularly humid and that “does reduce the risk somewhat”.The third heatwave was drier and longer lasting.Humidity levels are expected to fall in the fourth heatwave hitting this week.Agencies use the index to assess the severity of fire if it starts. It does not cover the chances of wildfires occurring.