Heavy fog across the UK forced cancellations of 100 more flights from London's Heathrow Airport on Tuesday.
The Met Office has issued a yellow "be aware" fog weather warning for most of southern England, the BBC reported.
A Heathrow spokesman said "persistent freezing fog" had reduced visibility at the airport and warned passengers to check their flight status.
On Monday, Heathrow, London City, Gatwick and Southampton airports also had cancellations.