Weather: Senegal, Cape Verde, The Gambia, Guinea, Guinea-Bissau, Sierra Leone

This is the end-point for the east-to-west march of weather systems across the Sahel. Senegal, as well as The Gambia (which it surrounds) is where easterly waves enter the Atlantic after dousing the region with intense rain and thunder. Outside of the June-to-October visit of the ITCZ and its easterly waves, Senegal is virtually rainless. Weather is hot year round, except on the northern coast, which juts into a cool Atlantic current. Africa's westernmost city, Dakar, is practically air-conditioned in the dry winter, averaging below 27°C/81°F by day, while much of the interior exceeds 32°C/90°F. More than three-quarters of Dakar's rain falls in August and September, although even then, most days remain dry. The Sahara influence extends to the Cape Verde islands 800km/500 miles offshore, which get virtually all their rain from August into early October. Further south, it's a far wetter story, with lots of cloud to boot. Average rainfall tops 1500mm/59in across nearly all of Guinea and Guinea-Bissau. The coastal reaches of Guinea and Sierra Leone average twice that amount – all during a single wet season, albeit a longer one as you move south. In Freetown (Sierra Leone), only winter could be considered dry, and the heat and humidity never really abate. The north Guinea highlands adjoining the Sahel are a bit less rainy and a touch cooler. Hail may accompany summer storms there.