São Tomé and Príncipe is a small island country composed of an archipelago located in the Gulf of Guinea of the equatorial Atlantic Ocean. The nation's main islands are São Tomé Island and Príncipe Island, for which the country is named. These are located about , respectively, off the northwest coast of Gabon in Central Africa. The nation's geographic coordinates are a latitude of 1°00′N and a longitude of 7°00′E. São Tomé and Príncipe constitute one of Africa's smallest countries, with of coastline. Both are part of an extinct volcanic mountain range, which also includes the island of Bioko in Equatorial Guinea to the northeast and Mount Cameroon on the mainland coast further northeast. São Tomé is long and wide and the more mountainous of the two islands. Its peaks reach - Pico de São Tomé. Principe is about long and wide, making it the smaller of the two. Its peaks reach - Pico de Príncipe. This makes the total land area of the country , about five times the size of Washington, D.C. Both islands are crossed by swift streams radiating down the mountains through lush forest and cropland to the sea. Both islands at a distance of . The equator lies immediately south of São Tomé Island, passing through an islet Ilhéu das Rolas. The Pico Cão Grande (Great Dog Peak) is a landmark volcanic plug peak, located at in southern São Tomé. It rises dramatically over above the surrounding terrain and the summit is above sea level. Climate At sea level, the climate is tropical—hot and humid with average yearly temperatures of about and little daily variation. At the interior's higher altitudes, the average yearly temperature is , and nights are generally cool. Annual rainfall varies from on the southwestern slopes to in the northern lowlands. The rainy season runs from October to May. Climate change Between 1950 and 2010, São Tomé and Príncipe experienced an increase of 1.5 °C in average annual temperature due to climate change. The country is considered highly vulnerable to its impacts. Climate change is projected to lead to an increased number of warm days and nights, hotter temperatures and increased precipitation. Sea level rise and saltwater intrusion will be major issues for the islands and climate change will have major impacts on agriculture in the country. The government began developing a National Adaptation Plan in 2022 to implement climate adaptation efforts,