The island of Symi has an area of 58 square kilometers and together with the surrounding islets a total of 65 square kilometers. (Ny mos, Sesklia, the islands of Ares and Diavates)It is 13 km long and 8 km long with 86 km circumference. According to the 2011 census, the population is 2590 inhabitants . The highest mountain is Vigla (616m). The rocks consist mainly of limestone.
The climate of Symi is characterized by bright sunshine, warm and dry summers, sparse rain i n winter. On the central part of the island, there are forests with native cypress tre es, as well as pines, barbs and the Greek strawberry tree. The shrubs are predominantly sage, E rica(tree Heath), thyme and mastic, while there is a local type of (Origanum symes) aromatic oregano. As far as crops are concerned, there are figs, apples, plums, o lives, vines, almonds. There are few sources of water on the island with small amounts of water that cannot meet the water needs.
In Symi, the first desalination works in Greece, were on the main square of Gialos, but the project failed due to poor water qu ality as well as drilling. Thus, municipal or private cisterns were built to store rainwat er. With the tourist development of the island, water was not enough, and as on other islands, the water was transported on water ships, a solution that is ve ry expensive. In recent years, Symi has been one of the islands that have been giv en a desalination plant for drinking water.