Hello May/Juni are really windy in Viganj, because the air is hot and the water is little bit colder, and the season of wind mistral starts. Last Juni 2012 was in Viganj really windy, every day from 10:00- 11:00 mistral wind start till 18:00, about 15kn-25kn. The water is not so cold but it is better to wear a wetsuit.
Also you have few camping places directly on the spot, there are people on the camping places but it is not so crowed like in the summer.
For more information and pictures go herehttp://www.windsurfing-kitesurfing-viganj.com/#!gallery