Lastovo possesses all the basic characteristics of the Mediterranean climate dominated by mild, moist winters and warm, long and dry summers. The average annual temperature of the island is ca. 15C, while the average annual rainfall is 687 mm. The air moisture of the island is ca. 70% only in July and August falls to 65%. The dominant winds are Jugo (warm, moist and steady) and maestral (NW direction).
The island spreads over 50 square kilometers. Its dolomitic valleys are located between limy hills and they often contain layers of red soil and quartz sand. The valleys are often surrounded by mild calcareous slopes rich in caves.
The coast-line is mainly steep and the surrounding sea is deep. Although the covers are sparse, yet the island has two deep bays. One of them, Skrivena luka (sheltered port), is situated on the southern part of Lastovo, between the cape of Strizevo and the cape of Veljo more (great sea). Here the sea has made a deep cut into the land. The other bay formed by Veli Lago and Mali Lago connected by a narrow passage - Most (bridge) is located between Prizba and the village of Lastovo.
Lastovo is the Adriatic island richest in natural forests. Particularly various and lively is its underwater life. There are no richer fishing areas in the Adriatic than those of Lastovo, especially where small bluefish, lobsters and many kinds of high-priced food fish like John Dory and Grooper are concerned. On the island poisonous snakes simply dont exists.