Gatwick Airport reopened at 0600 GMT after closing overnight, but passengers were told to expect further disruption.
A Gatwick spokesman said 600 flights would leave on Tuesday and measures were in place to cope with any more snow.
However, some knock-on delays and cancellations are likely throughout the day, due to the ongoing impact of snow across Northern Europe. Their advice to passengers remains the same - check with airline’s website to confirm the status of your flight.
Heathrow Airport is operating a reduced flight schedule of no more than a third of all flights until 0600 GMT on Wednesday, and there are delays at regional airports across the UK.
Further snow is forecast across Europe today and there may be further delays and cancellations.
Airport operator BAA said Heathrow’s south runway would remain closed on Tuesday and advised people not to travel to the airport unless their airline had confirmed the booking.
British Airways said it was suffering "significant disruption" in and out of Heathrow, especially to its short-haul schedules.
The government has agreed to relax regulations on night flights at Heathrow, allowing for arrivals until 0100 GMT each day until Christmas, while flights into London will be allowed to operate 24 hours a day.
Edinburgh, Aberdeen, Glasgow, Birmingham, Luton, London City, Bristol, Cardiff and Southampton airports say all flights would be subject to delays and cancellations.
The Foreign Office warns of disruption to road, rail and air travel in France, with delays in parts of Germany, Ireland, Italy, the Netherlands and Switzerland.