Seven flights at Heathrow Airport and three at London City Airport were cancelled by 6:30am on November 9, 2026, as thick fog reduced visibility to 50 metres or less across London and South East England. A yellow weather warning from the Met Office was in effect from early morning until 11am covering these areas.
Meteorological Conditions Behind Fog Development
Met Office operational meteorologist Niamh Murray said the fog resulted from a combination of seasonal factors. “With autumn and winter and getting fog during this time of year, we get much longer nights, and that allows temperatures to fall away,” she explained. “We get a longer
period of cooling and also the temperatures are much lower, so they’re much closer to the temperature that we need for the air to become saturated and therefore form fog.” Light winds and clear skies contributed further to fog formation. Murray noted that if temperatures drop below zero degrees Celsius, fog can persist stubbornly into the next day.
Road Travel Impact and Safety Warnings
The thick fog also affected road travel, resulting in a crash involving over 30 vehicles on the M20 motorway between junctions 8 and 9 near Maidstone, Kent. The collision on the evening of November 7 led to the motorway being closed for
nearly 12 hours and caused serious injuries to two people.
Edmund King, president of the Automobile Association (AA), urged drivers to exercise caution. He said, “Fog can transform a familiar road in a matter of minutes, so drivers need to be prepared to adapt their speed and leave more room between themselves and the vehicle ahead.” King cautioned against simply following the rear lights of the car in front, calling it a common mistake that can cause unsafe close distances. He emphasized allowing extra time and driving according to visible conditions.
Impact on Travellers and Travel Safety Advice
The flight cancellations disrupted normal air traffic at Heathrow
and London City airports during the morning of November 9. Reduced visibility also complicated both airport and road travel schedules. The Met Office’s yellow warning signalled difficult travel conditions across London and much of the South East until mid-morning.
Authorities and safety experts stressed the importance of adjusting travel plans to account for fog. Drivers were specifically advised to slow down and maintain greater distance from other vehicles during foggy conditions to mitigate accident risks.
