Thick fog banks over Heathrow caused severe disruption to the flight schedule earlier today, with more than 50 flights cancelled or diverted elsewhere.
Though most of the fog has lifted by now, it is expected to return tonight, which again may cause disruption towards the morning.
A spokesman for the Met Office said “The thick fog is expected to return again tonight so Heathrow could be pretty foggy again tomorrow morning.”
“Areas of fog are expected to form during Sunday night becoming widespread and dense in places by Monday morning.”
Passengers due to fly into the airport are advised to check with their airline.