Stansted Airport reopened its runway shortly after 11am and staff said they were working to clear a backlog of flights.
A spokesman said around 100 flights were cancelled after the runway was closed because of heavy snow shortly after 6am.
He said the disruption was likely to have a knock-on effect throughout the day.
Thousands of people were left waiting in the main terminal as a result of the closure.
An official said travellers should check with airlines before setting off for the airport.