If you're taking advantage of the Christmas break to venture to sunnier (or snowier) climes, beware: fog is affecting flights into and out of Heathrow airport.
The airport tweeted this morning that passengers should check flight status with their airline.
Foggy weather may affect scheduled flights today. Please kindly check your flight status with your airline: https://t.co/20RhenlzpJ— Heathrow Airport (@HeathrowAirport) December 28, 2016
City Airport was also affected, warning that there may be delays and cancellations.
Passengers please note due to current weather conditions there may be delays & cancellations, please check with airline for flight info.— London City Airport (@LondonCityAir) December 28, 2016
In response to a passenger enquiry, it tweeted that it was waiting for conditions to improve before flights could land.
However, other airports were less affected by the fog, with flights at Gatwick, Stansted and Luton all reporting normal conditions.
Christmas train woes
Travellers to airports around the capital have been beset by delays and cancellations across the train and Tube networks over the Christmas break.
That included Gatwick Express, which did not run any services into or out of Victoria station on Boxing Day.
Meanwhile, Paddington station is closed until tomorrow to make way for Crossrail work - meaning Heathrow Connect services are also disrupted.