On Monday morning, November 9, 2026, seven flights at Heathrow Airport and three flights at London City Airport were cancelled by 6:30am due to dense fog across London. The Met Office issued a yellow weather warning covering London and most of South East England until 11am, warning visibility could fall to 50 metres or less.
Meteorological Conditions Behind the Fog
The thick fog developed overnight as longer autumn and winter nights caused temperatures to drop and air saturation to form dense fog. Niamh Murray, a Met Office operational meteorologist, described the situation as the “perfect recipe” for fog formation, with light winds, clear skies, long
nights, and cooling temperatures that approach the dew point.
“With autumn and winter and getting fog during this time of year, we get much longer nights, and that allows temperatures to fall away,” Murray said. “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.”
Impact on Travelers and Airport Operations
The fog resulted in significant disruption at London’s two major airports this Monday morning. Flight cancellations at Heathrow and London City airports caused delays and cancellations, with low visibility conditions affecting
takeoff and landing operations. Visibility was expected to remain at or below 50 metres for several hours following the early cancellations.
Official Safety Warnings Related to Fog
Amid the hazardous driving and travel conditions caused by the fog, Edmund King, president of the AA (Automobile Association), urged motorists to adjust their speed and maintain greater distance between vehicles. He warned that fog can reduce road visibility rapidly, transforming familiar routes into dangerous conditions.
King stated, “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.”
He cautioned against relying solely on the rear lights of the vehicle in front, saying this could create a false sense of security and insufficient stopping distance.
These safety warnings coincide with weather conditions that have already caused severe travel disruptions on roads and urban transport networks in London and the South East as the fog persists into the morning hours.
