On Monday morning, November 9, 2026, dense fog led to cancellations of seven flights from London Heathrow Airport and three from London City Airport by 6:30 a.m. The visibility dropped to 50 metres or less, forcing disruptions at two of London’s primary airports.
Yellow Weather Warning and Fog Formation
The Met Office issued a yellow weather warning covering London and much of South East England until 11 a.m. The fog developed under a combination of light winds, clear skies, long autumnal nights, and falling temperatures, creating what Met Office meteorologist Niamh Murray described as the “perfect recipe” for fog. These conditions allowed temperatures to drop close
to or below freezing, enabling the air to saturate and fog to form and persist.
Official Advice on Fog and Driving Conditions
Niamh Murray explained that the longer nights in autumn and winter extend cooling periods, lowering temperatures enough for fog formation. The Automobile Association’s president, Edmund King, warned that fog can rapidly alter road conditions. He urged drivers to reduce speed, increase following distances, and avoid relying solely on the rear lights of preceding vehicles to maintain safety in low visibility. King emphasized allowing extra travel time and driving within the limits of visible road ahead.
M20 Motorway Crash and Closure
Fog was a factor in a severe multi-vehicle pile-up on
the M20 motorway in Kent near Maidstone. More than 30 vehicles collided between junctions 8 and 9 on Saturday evening prior to November 9. The crash caused serious injuries to two people and resulted in a motorway closure in both directions lasting nearly 12 hours. The road remained shut through much of the night before reopening.
The fog-related disruptions affected air and road travel across the London and South East region on November 9, with significant delays and cancellations reported during the early morning hours.
