Gatwick Airport has reopened its runway after heavy snowfall grounded aircraft on Monday evening.
The West Sussex airport said there were 696 flights scheduled on Tuesday with about 100,000 passengers expected to travel.
It warned passengers to expect delays and said 53 flights had been cancelled by 2100 GMT.
A total of 150 staff worked through the night to clear snow and ice from the runway.
On Monday passengers were told to go home rather than wait inside the terminal buildings.
A spokeswoman said the airport's runway reopened at 0600 GMT and the first departure was a Monarch flight to Innsbruck which took off at 0606 GMT.
She added: "Passengers planning to travel through Gatwick today, and for the rest of this week, should check the flight status on their airline's website first and only make their way to the airport if their flight has been confirmed."
Elsewhere in the county, Southeastern trains and Southern Railway said some routes on Tuesday would be affected by the weather.
A spokeswoman for Southeastern said: "It's inevitable that many services will be disrupted with cancellations and delays on many routes.
"Also some of our trains will have fewer carriages than they usually do, as a result of damage caused by the snow and ice."
Southern Railway said there were some alterations to services to the Sussex coast.
Both rail operators were resuming a normal service on Tuesday and said a normal timetable would run on Wednesday.
Motorists have also been urged to take extra care on the roads while temperatures remain low.