Boa Vista weather: the climate of Cape Verde's dune island

Boa Vista weather at a glance

Boa Vista is the easternmost island of Cape Verde and, like Sal, low and flat: its highest point, Monte Estância, reaches only 387 m, so clouds drift over without dropping much rain. The cool Canary Current and the north-east trade winds keep the heat in check, and the result is a semi-desert climate with a narrow range. In Sal Rei, average highs move between 24 °C in February and March and 29 °C in September and October, and nights between 20 °C and 25 °C. More about the island in our Boa Vista guide.

The climate table gives, for each month, the average high and low in Sal Rei, the sea temperature and the rainfall. The figures come from ERA5 reanalysis data for 2015-2024, with sea temperatures for 2022-2025, the same method as our Sal weather guide, and the two islands come out almost identical. Inland and towards the south, around Santa Mónica, the same data suggest afternoons a degree or two warmer and nights about a degree cooler than in town. They describe a typical month, not a forecast.

Boa Vista weather in December, January and February

Winter is the main season on Boa Vista, and the weather explains why. In December Sal Rei averages about 26 °C by day and 22 °C at night, with the sea at 25 °C; January brings 25 °C and 20 °C, with a sea of 24 °C; and February, the coolest month together with March, 24 °C and 20 °C, with the sea at 23 °C. December and January are practically dry, and February's average of about 10 mm usually means a passing shower or two.

It feels fresher than the figures suggest. The trade winds blow hardest from about December to May, evenings on a terrace call for a long-sleeved top, and on the exposed west-coast beaches, where most resorts stand, the wind can whip up sand in the afternoon; a resort with wind-protected pool areas makes a real difference. The month pages give more detail for December, January and February, and if you are coming for the festive season, read Cape Verde at Christmas and New Year.

Wind, waves and kitesurfing

The north-east trade winds are the defining feature of Boa Vista's weather. In the reanalysis data the average wind speed in Sal Rei is about 22-25 km/h from December to May and drops to about 15-17 km/h from July to September, when calm days become more common. The wind is what makes the heat comfortable, and what keeps the dunes of the Viana desert on the move.

Winter and spring are the season for windsurfing and kitesurfing at Praia de Estoril, just south of Sal Rei; see kitesurfing in Cape Verde. The same months bring Atlantic swell to the exposed coasts, and some beaches, such as Santa Mónica, have a powerful undertow all year. Swim where the water is calmer, around Sal Rei and on parts of Praia de Chaves, follow the flags where there are any and check our beach guide.

Saharan haze: the bruma seca

Between roughly November and March, and most often from December to February, the Harmattan can carry fine dust from the Sahara over the island. Locals call the haze bruma seca: the sky turns milky, the sun pales and the horizon disappears, sometimes for several days. Boa Vista is the island closest to Africa, and the UK Foreign Office notes that sandstorms can affect flights there in particular.

Domestic flights are the first to be cancelled when visibility drops, and international flights are occasionally delayed too. If you are combining Boa Vista with another island, leave a spare day before your flight home and read ferries and flights between the islands; if you have asthma, keep your medication to hand.

Spring and early summer: March to July

March has the coolest sea of the year, about 23 °C, and with highs of 24-25 °C until May the weather stays dry, sunny and windy. It is also the season of the humpback whales, which gather off Boa Vista to breed from about March to May; boats leave from Sal Rei, see whale watching.

June and July are a little warmer, at 26-27 °C, the wind starts to ease and the sea warms to 24-26 °C. The first loggerhead turtles come ashore in June, and from July the nesting season is in full swing.

Late summer and the short wet season

From August to October Boa Vista is at its hottest and most humid, with highs of 28-29 °C, nights of 24-25 °C and the sea at 27-28 °C. This is also when most of the year's rain falls: about 35 mm in August, 45 mm in September and 15 mm in October, out of roughly 130 mm a year, usually as short heavy showers or a stormy day rather than days of grey weather. Most storms that form near Cape Verde in the hurricane season move away to the west, and a direct hit is rare.

These are the peak months of the turtle season: Boa Vista is one of the most important nesting sites for the loggerhead turtle in the Atlantic, and licensed guided night walks run on its beaches. See turtle watching for how they work. November is the transition back to the dry season, still about 28 °C, with a sea of 27 °C and the wind picking up again.

Which month to choose

For the warmest sea and lighter wind, choose July to November, accepting more humidity and a few showers from August to October. For dry, sunny days, kitesurfing and whales, choose December to May, with stronger wind and a cooler sea. To weigh the weather against prices and school holidays, see the best time to visit Cape Verde, and if you are still deciding between the two beach islands, read Sal or Boa Vista?.