Soyo has a tropical climate with two distinct seasons. The dry season runs roughly from June to September, when rainfall drops sharply and temperatures are moderate — around 22 to 27 degrees Celsius. This is the more comfortable time to visit, and road conditions are at their best, which matters if you are travelling overland.
The rainy season runs from October through May, peaking in November and again in March and April. Rainfall can be heavy, and the unpaved roads leading to Soyo can become very difficult or impassable. Humidity is high throughout the year.
For most travellers, the dry season between July and September is the practical choice. The estuary and coastline are at their most accessible, and the skies are clearer. The dry season is also cooler — if you are sensitive to heat and humidity, avoid the wet season months.
There is no peak tourist season as such. Soyo sees very few leisure tourists at any time of year, so you are unlikely to encounter crowds regardless of when you go.