The Island’s Climate
The climate on Formentera is sub arid, and the long hot summers can hit the mid-80s in August. The heat is amplified when the dry leveche wind blows across from Africa, but most of the time the local wind has a cooling effect. Formentera weather is generally excellent all year round.
From May to September the island enjoys over 10 hours of sunshine every day, and this halves during the winter months. The winters are fairly mild, with temperatures of around 60 degrees Fahrenheit between November and April.
The off-season weather in Formentera is not harsh at all: you can spend a very enjoyable November and December on the island and will probably be able to swim and sunbathe on all but a handful of the days (mind you the sea can get a bit chilly in December, so swimming is not for everyone). The coldest the sea drops to is 55 degrees Fahrenheit in February. In August it spikes at around 77 Fahrenheit, but in the shallow waters it feels a lot warmer.
March and October are the wettest months with two to three inches of rain, but outside these months rainfall is not a prominent feature of Formentera weather.