High season in Turks and Caicos runs roughly from January through March, with the usual extra-high rates during the Christmas and New Year's holiday period. Several hotels on Provo offer shoulder-season rates in April and May. During the off-season, rates are reduced substantially, as much as 40%.
There aren't really any major festivals or events to draw travelers. The main draw in the islands is consistently good weather, (except for the occasional tropical storm).