Spring is a wonderful time to visit Bosa. The weather warms up (though you will still need a jumper occasionally) and wild flowers cover the hills and fields and roadsides. Many different kinds of orchids can be found. Generally the second half of April is the best for wild flowers. Fresh spring vegetables are in the shops, with the first peas and broad beans. Daytime temperatures will often reach the mid 20s, but drop at night.
Summer can be very hot, occasionally reaching 30 degrees or more in the afternoon. The sea has warmed up and people make for the beach. Although there can be the occasional rain storm, it is rare. The swimming is great at Bosa Marina, and the little coves North and South of there offer a choice of less crowded beaches, rock pools, sand dunes and coastal walks.
Autumn, once again, brings the possibility of rain (but not much) and when it does rain it tends to be heavy and then clear up again. The temperatures become less severe, and there is the possibility of wild mushrooms in the restaurants and shops.