Heavy fog grounds London flights as Heathrow and City axe departures

Heathrow lost seven flights and London City three by 6.30am as fog clamped down on the capital, according to standard.co.uk. Forecasters warned visibility could drop to 50 metres or less in the soupy conditions. A yellow weather warning covering London and most of the South East runs until 11am, with the Met Office flagging difficult travel through the morning.

The fog has a straightforward recipe behind it, a Met Office forecaster told the Press Association. Longer autumn nights let temperatures fall away, and the air sits much closer to the point where it saturates. Light winds and clear skies do the rest — enough breeze to form fog, but not enough to shift it. When temperatures go negative, the forecaster said, the fog can be stubborn to clear the next day.

Drivers are being told to adjust. The AA's Edmund King said fog can transform a familiar road in minutes, so motorists should slow down and leave more room. His biggest warning: don't just follow the tail lights ahead. It feels safe, he said, but you may be too close to stop if that car brakes. His advice — allow extra time, drive to what you can actually see, and remember there's no prize for arriving early.

The caution carries weight. A crash involving more than 30 vehicles in foggy conditions shut a motorway for nearly 12 hours. With the warning live until 11am, anyone flying out of Heathrow or London City should check their flight before heading to the airport.