All Swedavia airports, which include most of Sweden's largest, showed a decline in passenger numbers in April. Stockholm Bromma decreased by 27 percent and Stockholm Arlanda by 23 percent. Gothenburg Landvetter fell by 21 percent.
Some 1.7 million people passed through the company's airports last month. International traffic decreased by 19 percent to 1 million passengers, while domestic traffic declined by 32 percent to 700,000, Swedavia said in a statement.
"The first part of April showed a strong performance, but the traffic disruption due to the ash cloud from April 15th to 21th caused a passenger shortfall of about 600,000 travellers," Mats Sigurdson, director of aviation marketing at Swedavia, said in a statement. "Even after traffic restarted, there were a number of delays and flight cancellations."
From January to April, the number of air passengers at Swedavia airports fell by four percent from the same period in 2009. The number of international passengers decreased by three percent and domestic passengers by four percent.
"We saw the smallest decline in intercontinental travel. This was due to less sensitivity to delays and traffic diversions, but also because Sweden received several departures when [Copenhagen's] Kastrup was closed," said Mats Sigurdson.
The number of landings for scheduled and charter flights fell by 22 percent in April compared with the corresponding month last year. International landings declined by 16 percent and domestic by 27 percent. From January to April, the number of landings decreased eight percent to 59,500.
Swedavia was previously part of the aviation authority LFV (Luftfartsverket, or Civil Aviation Administration) until April 1st, when Swedavia was formed and LFV transferred over responsibility for airport ownership and operation.