Het weer in Sao Tomé in september

Forum posters describing December-into-January visits report notably dry, sunny stretches: one visitor saw only about a day's worth of rain across their whole trip, and another spanning two weeks of January reported no rain at all except one roughly hour-long shower early on. Posters consistently cite daytime temperatures around 30C as typical for this window. It is worth noting that the full 12-month climate record shows January is actually one of São Tomé and Príncipe's wetter months overall (around 24 rainy days), with the islands' genuine short dry season (locally the "gravana") falling June through September instead - these travelers' good fortune with dry conditions may reflect normal day-to-day variability within a wetter month rather than the seasonal norm. Posters generally rate January as warm and humid for São Tomé, with a real chance of a lucky dry stretch but no guarantee of one given the time of year.

Forum posters name July, alongside August and January, as part of the islands' dry season, though posters are direct that conditions vary meaningfully by location even within Sao Tome itself - dry in the north, rain most of the day in the center, and a genuine 50/50 mix in the south. Posters describe the overall climate as equatorial and consistently warm and humid regardless of season, with even 'dry season' rain typically limited to an hour or so rather than an all-day event when it does happen. Posters describe skies as often cloudy generally, but flag Ilheu das Rolas specifically as a reliable spot for sunnier days. Posters generally rate July as a reasonable time to visit, provided visitors understand 'dry season' here is relative and location-dependent rather than a guarantee of sunshine everywhere on the islands.