WEATHER AND WHEN TO VISIT
Sunny, warm climate
It is said that there are over 300 days of sunshine a year in Sardinia. April and May are beautiful with spectacular carpets of wild flowers, lush vegetation and warm weather (20 C / 68 F). June is like summer in northern Europe but with more reliable sun and heat (26C / 79F). The weather is very hot, sunny and dry in July and August (32C / 92 F). September and early October bring less heat (25 C / 77 F) and it is usually warm enough to walk comfortably with sandals and shorts during the day, and even go to the beach. The winter months from November to February are cooler, and this is when the rain usually falls - often in dramatic storms. It can be nice to go for a short break during these winter months but don't expect to sunbathe on the beach.
Visiting during festivals
It is especially interesting to visit Bosa during festivals. The streets are filled with people -- in costume, making merry in the small cantinas, dancing and singing, gathered around bonfires. Some festivals in Bosa are devoted to the Madonna, such as Santa Maria del Mare in early August when hundreds of boats come down the river, or Regnos Altos in mid-September, when there are home-made altars in the streets of the old town, and processions as the statue of the Madonna is carried and the houses blessed. Others, such as Carnevale in February, are more obviously pagan in character, celebrating fertility and based on local legend. Easter and Holy Week are especially evocative with processions, polyphonic singing and Biblical scenes enacted on the streets and in the churches. There are many other local festivals all over Sardinia. If you chance across a procession or festival while you are visiting - do join in!
Additionally there are also many modern festive events, such as Bos'Art, a month long arts festival in August, as well as open-air theatrical, dance and music events on the streets or near the beach during the warmer months.