Heavy fog that severely limits visibility has led to further cancellations and delays of dozens of flights at Heathrow and Gatwick, and is forecast to persist through the weekend.

The murky weather has shrouded much of the country over the past few days and showed little sign of abating on Saturday. In some areas, thick fog patches could reduce visibility to just 100 metres, the Met Office said.

The UK’s main air traffic control provider, Nats, said some UK airports continued to be affected by “widespread” fog and that air restrictions would remain in places with low visibility. The BBC reported that 20 flights at Heathrow had already been cancelled on Saturday, with another 29 delayed. At Gatwick, 26 had been delayed and one cancelled, after a series of cancellations on Friday.

The national weather service has not yet issued warnings for fog but said it would monitor the situation. The Met Office meteorologist Liam Eslick said: “It’s that time of year when people are travelling around the country a lot and there are a lot of people on the roads.

“There is a lot of fog covering much of England, mainly the south-east and central England, but the rest of the country is seeing quite a bit of thick fog too … It will be pretty murky on Saturday morning and there will still be fog patches that will take a little longer to clear.”

On Friday, dozens of flights from airports across the UK were cancelled and hundreds delayed, according to the flight-tracking website Flightradar24.

A spokesperson for Gatwick airport, in West Sussex, confirmed that air traffic restrictions remained in place on Saturday. “Some flights may be delayed throughout the day,” they said. “London Gatwick apologises for any inconvenience. Passengers should contact their airline for further information.”

Irem, 36, said her flight from Cologne, Germany, to Manchester airport had been delayed by more than six hours on Friday due to fog in the north of England. “I suppose we’re lucky we’re still going to see [her husband’s family in north Wales] tomorrow,” she told the BBC.

One flight from Istanbul to Gatwick was delayed by 10 hours, the flight status website Cirium showed. “Some passengers got hotel, some were stranded at airports because of confusion,” Dr Shama Junejo said on X.

The Met Office has advised motorists to go steady when they are driving in fog. Lingering low cloud should start to clear on Sunday, Eslick said, with winds forecast to “pick up and turn over these cloudy and murky conditions to help clear the fog”.

The recent murky conditions are less likely to return in the last couple of days of the year but people should not hold out hope for much winter sunshine. “It looks like it won’t be as dank and horrible [early next week] but it will still be wet and windy across much of the country,” Eslick said.