Despite the usual group of Olympic nay-sayers, it appears that London will indeed benefit from the Games. A new Amadeus report is forecasting a 13 percent increase in visitation for London during the Games with the United States as the biggest source market.

Released in conjunction with ForwardKeys, the range of travel data trends, based on actual global air reservations, details the impact of the London 2012 Olympics with approximately 50 days to go and provides a country-by-country view of where visitors to London during the Olympics period are coming from. According to the study, the U.S. will account for 19 percent of total expected arrivals. Germany is the second largest source market, responsible for 8 percent of total expected arrivals and BRICS nations (Brazil, Russia, India, China and South Africa) are emerging as important source nations as well.

Europe will be the source region for the greatest proportion of arrivals to London during the period of the Games, accounting for 46 percent of total expected arrivals. North America is second with a 23 percent share and Asia is the third biggest source region with 9 percent of arrivals, a significant increase of 27 percent on 2011 bookings. Visitors from New York City to London will be up 48 percent for this period compared with 2011, while visitors from San Francisco will be up 29 percent compared with the same period last year.

From the Olympics’ opening ceremony throughout the duration of the Games, London will experience a high level of occupancy, with numbers 7 percent higher than last year for the period between the opening and closing ceremonies. The greatest increase in occupancy compared with 2011 is between Aug. 4 and Aug. 8.

Londoners also apparently intend to remain in the city and enjoy the spectacle during the Olympics period, according to the Amadeus survey. Departures to any destination from London for the period before the opening ceremony are 5 percent below 2011 levels. Across the whole summer (from July 2 to Sept. 2), 2 percent fewer Londoners will leave the city than in 2011. At the same time, it seems that Londoners aren’t forgoing a holiday altogether, simply deferring it; three weeks after the closing ceremony, departures will increase to 10 percent more than in the same period in 2011.

The forecast provided by ForwardKeys.com, a business intelligence tool launched by Forward Data in partnership with Amadeus, is based on actual air booking data available as of May 12, 2012. This analysis is the second in a series of forecast reports examining how the London 2012 Olympics is affecting global travel trends.