The climate in Guinea-Bissau

Climate

The Republic of Guinea-Bissau is located between Ecuador and the Tropic of Cancer, which puts the country in a tropical climate zone. The tropical climate is characterized by a clear definition of two seasons throughout the year: winter, also known as the dry season, and summer, also called the rainy season. Basically, trade winds are the cause because there are alternating dry and rainy seasons. During the summer (rainy season), the land winds bring rain and, in winter (dry season), the sea winds keep the savanna region dry. Keeping in mind that trade winds are stronger during the summer.

More specifically, the country’s climate is characterized as being tropical humid, a designation also known as tropical savannah climate or tropical climate with dry season, among other names. This is due to the country’s proximity to the sea, which raises its humidity levels, making Guinea-Bissau a region evidently influenced by maritimity and, consequently, wetter. This type of climate shares some similar characteristics with the tropical monsoon climate, however it receives less annual rainfall compared to the tropical monsoon climate.

Overall, the climate in the country is characteristically hot and humid, with temperatures being quite high throughout the year. Throughout the year, the temperature generally ranges from 19 °C to 35 °C.  Rarely do temperatures drop by 17 °C or rise beyond 38 °C, so the average annual temperature in Guinea-Bissau is 27.7 degrees. The fact that the country does not have higher areas or variations in altitude in its geography is one of the justifications for the absence of milder temperatures.

Winter: Dry season

In the Guinean country, the dry season takes place between November and April, with the months of December and January being the freshest. During the dry season, the days are warm and sunny, however the nights are colder. There is little rain falling during this time of year and the atmosphere is dried by the so-called “Harmattan” wind – a warm, dry wind that occurs near the Sahara desert, whose top speed is 36 km/h. Harmatão wind in Portuguese blows from the interior of Africa towards the Atlantic Ocean between December and February – which justifies the coolest months of the year in Guinea-Bissau. This phenomenon favors soil cleaning for planting.

Summer: Rainy season

In Guinea-Bissau, the rainy season takes place between the months of May and October, with the months of July and August being the rainiest of the year. As a general feature, the rainy season facilitates the growth of vegetation, besides often bringing improvements in air and water quality. However, floods also occur in rivers and lakes, which can lead to decreased nutrients in the soil and increased erosion, as well as being a time when land transport becomes more difficult.