U.S. Ambassador to Japan Thomas Foley was the first to predict that the forthcoming G8 summit on Okinawa might have to be held with the participants wearing sport or aloha shirts instead of formal or business attire.

Foley had just returned from an inspection visit to summit facilities several weeks ago. He told U.S. reporters at a private embassy gathering that his main impression was "It was very hot in Okinawa and bound to get hotter."

Meteorologists say the Okinawa weather on July 21-23 is expected to be at least 28.3 C with humidity over 80 percent.