A Met Office yellow weather warning for dense fog covering London and large parts of England and Wales came into force overnight into Sunday, 1 November, bringing delays to flights at Heathrow Airport.
The warning was issued at 23:18 GMT on Saturday 31 October and covered Greater London and the South East alongside the South West, the Midlands, the East of England, North West England, Yorkshire and Humber, and parts of Wales. It was due to lift by 10am, but the Met Office said some fog patches could last into the afternoon, with visibility reduced to less than 100 metres in places.
"People can expect traffic delays because of the heavy fog and those flying should also plan for delayed or cancelled flights," the Met Office said, the Evening Standard reported, which covered the warning specifically as it applied to London.
Flight-tracking data from Flightradar24 showed Heathrow's average delay running at around 20 minutes by mid-morning, with 10% of Sunday's departures, 67 flights, delayed and 1%, nine flights, cancelled, a disruption level the tracker classed as low but rising.
Ryanair issued a UK-wide notice to passengers on Sunday morning saying that "due to heavy fog, some flights to and from the UK may be delayed today," and that affected customers would be contacted directly through its app, the Mirror reported.
The fog warning was the second to cover London in three days, following an earlier one on Friday, the Standard said, and came days after Storms Austen and Boelo brought England its wettest week since October 2024.
There is no indication of a wider suspension of flights at Heathrow, and the figures so far point to modest delays rather than mass cancellations. Passengers travelling through Heathrow on Sunday should still check their flight status directly with their airline before setting off.
What this means for your journey: if fog adds time to your journey to the airport, our parking guide has options to build in a buffer, or see our public transport guide for rail and bus alternatives into Heathrow.