Ireland's airspace is due to reopen this afternoon after a brief closure over the course of the weekend.

Volcanic ash form the Eyjafallajokull volcano affected the travel plans of at least 36,000 passengers, with almost 300 flights been canceled.

Initially, airports in Donegal, Sligo, Belfast, Galway and Knock closed yesterday morning, followed by Dublin airport at 7 p.m. (all times local). Knock and Galway have now reopened. Dublin is due to reopen today at noon and Donegal is due to open at 2 p.m.

The Irish Aviation Authority (IAA) had extended the airport closure due to weather forecasts, which indicted "an increased quantity of ash over Irish airspace."

The IAA said that this week’s outlook is positive, and it does not expect any further restrictions for at least another 48 hours.

Passengers have been asked to check their airlines websites for flight updates before they travel to the airport.

Aer Lingus canceled all flights until midday today, but all flights are expected to resume at 1 p.m. today.

Dublin Airport Authority spokeswoman Siobhan Moore said that passengers whose flights had been canceled should receive updates by contacting their airline and should avoid traveling to the airport.

Northern Ireland's three airports were also closed yesterday and are expected to resume at 1pm today.

Britain, France and the Netherlands also experienced significant delays due to the volcanic ash cloud.

The widespread disruption is having a massive economic impact on businesses and tourism.

The IAA revealed that 4,743 flights to and from Ireland were canceled during April 15 - May 10 at a cost of $10 million to the IAA.

During the same period, a total of 104,000 flights were canceled in Europe.

The International Air Transport Association (IATA) has estimated that airlines lost $1.9billion during April alone.