Stansted airport had to temporarily close its runway on Wednesday (December 27) to allow staff to clear snow.
The runway at the Essex airport was reopened at around 10am to allow flights to resume but passengers have been warned about delays and cancellations.
“Due to adverse weather conditions, the runway was temporarily closed for snow clearance and has now reopened,” said Stansted in a statement.
“Flight delays and cancellations are expected and we advise passengers to check the status of their flight with the airline before travelling to the airport.
Stansted urged passengers to listen to traffic and transport updates and allow extra time for travel to the airport.
Luton airport also warned about potential delays and cancellations to flights on Wednesday.
“The airport is open and the runway is operational,” said the airport. “Some flights may be subject to delay and/or cancellation. Passengers should check with their airline for the status of their flight.
“We advise all passengers to check traffic and travel information before setting off and allow extra time to get to the airport.”
Ryanair said that the snow in the UK had caused delays and some cancellations to flights.
"We regret to advise customers that due to heavy snowfall across the UK, some flights have been delayed and we have also been forced to cancel a number of flights," added the airlien in a statement.
"We kindly ask that all passengers check the status of your flight on our website before you set off for the airport."