Dense Fog Forces Cancellations at Heathrow and London City Airports; Yellow Warning in Force
Why It MattersFog at London's airports shows how a single overnight weather pattern can cut visibility enough to trigger cancellations at once, tying the reliability of hub and city-airport schedules to low-visibility procedures.
What happened
Flights at Heathrow and London City airports were cancelled on Monday as dense fog covered London. Visibility was forecast to fall to as little as 50 metres in some areas.
By 6.30am, seven departures or arrivals had been cancelled at Heathrow and three at London City.
A Met Office yellow weather warning covering London and much of the South East remained in force until 11am. Met Office operational meteorologist Niamh Murray said clear skies, light winds and long overnight cooling had created the "perfect recipe" for fog. The Met Office cautioned that fog could prove stubborn to clear in some places.
Industry impact & what to watch
Fog is one of the weather conditions that most directly limits airport throughput, because low visibility forces tighter spacing between movements and can halt operations altogether. When the same overnight pattern covers an entire region, several airports are affected at the same time, which is why Heathrow and London City were hit together on Monday.
For business aviation, which often uses airports around London and the South East, the same low-visibility conditions affect schedules and routing. The practical consequence is that early-morning departures and arrivals carry the greatest exposure when fog settles overnight.
The next milestone is the 11am expiry of the yellow warning. How quickly the fog clears after that point will determine how long the disruption lasts and how far the cancellations extend beyond the early-morning count.
