São Tomé & Principe– when to go
While Sao Tome and Principe are all year round destinations, the most popular time of visit are among the one of the two dry seasons: either between June and September or around January/February. For divers the best months are between December and March. Whalewatching is between mid July till mid September. July, August and September are the peak months for fishing for Atlantic blue marlin and best fishing for Sailfish is between September and December.
Weather
Sao Tome and Principe have an equatorial climate with heavy rainfall, high temperatures and humidity. The south of the main island, being mountainous , is wetter than the north. The main dry season is from early June to late September. There is another dry season, the 'Pequenha Gravana', from the end of December to the start of February. For most of the São Tomé and Principe area, daytime temperatures are consistently around the 29°C (84°F). Several microclimates also exist, particularly on São Tomé island, where the north has a drier, savannah-like climate and the south receives much more rain, even during the dry season.