The Met Office has issued a new yellow weather warning for fog covering Greater London and Heathrow, in force from 6pm on Sunday 8 November until 11am on Monday 9 November, with forecasters warning that flights could be delayed or cancelled as visibility falls as low as 50 metres in places.
According to the Met Office's official warning, fog patches will form during Sunday evening and develop overnight, becoming extensive by Monday morning before clearing slowly later in the day. The warning area stretches across a large part of England and Wales, taking in London and South East England alongside the East Midlands, East of England, North West England, South West England, the West Midlands, Yorkshire and the Humber, and parts of Wales.
The Mirror reported on Sunday that the warning covers 85 areas for 17 hours, with forecasters flagging a direct risk to flights alongside possible bus and train disruption. The Met Office advised travellers to check conditions before setting out, leave extra time for journeys, and make sure fog lights are working, while anyone flying should check with their airline before heading to the airport.
The new warning comes just a day after Heathrow was named among the world's most delayed airports as an earlier bout of fog disruption deepened through Saturday, following a separate overnight fog warning that covered the airport into Saturday morning. As of Sunday afternoon, Heathrow's own departure boards were showing a handful of flights running behind schedule by 45 minutes or more, with no cancellations reported, though that picture can shift quickly once fog thickens overnight and across Monday morning, historically one of Heathrow's busiest periods.
Passengers travelling to or from Heathrow on Sunday evening or Monday morning should check their flight status directly with their airline before leaving home, allow extra time for the journey, and be prepared for the possibility of delays or cancellations if fog becomes dense overnight.
(weather.metoffice.gov.uk) and The Mirror.
What this means for your journey: fog tends to hit road journeys hardest, with slower approach roads and busier drop-off areas, so it is worth checking our /public-transport/ page for rail options into the airport that are less affected by poor visibility than driving.