Kozani () is one of the regional units of Greece. It is part of the region of Western Macedonia, in the geographic region of Macedonia. Its capital is the city of Kozani. Geography Kozani borders the regional units of Kastoria to the west and northwest, Florina to the north, Pella to the northeast, Imathia and Pieria to the east, Larissa (part of Thessaly) to the southeast, and Grevena to the south. The main mountain ranges are Askio in the northwest, Voio in the west, Vermio in the northeast and the Pierian Mountains in the southeast. The river Aliakmon flows through the southern part, and through the large reservoir Lake Polyfytos. Lignite is mined in the north, around Ptolemaida. Climate Its climate ranges from continental to mountainous. Kozani has warm to hot summers and cool winters, cooler than Thessaloniki, the mountainous, the western and the eastern portions receive cold winters and features snow. Its sunshine days are days shorter than the south and by the coastline, it is rainier than the south. Temperatures range from during the summer months. Administration The regional unit Kozani is subdivided into 5 municipalities. These are (number as in the map in the infobox): Eordaia (2) Kozani (1) Servia (4) Velventos (5) Voio (3) Prefecture Kozani was created as a prefecture () in 1915. As a part of the 2011 Kallikratis government reform, the regional unit Kozani was created out of the former prefecture Kozani. The prefecture had the same territory as the present regional unit. At the same time, the municipalities were reorganised. The municipality Servia-Velventos was split into the municipalities Servia and Velventos in 2019. Provinces Kozani had three provinces: Kozani Province - Kozani Eordea Province - Ptolemaida Voio Province - Siatista History Early years The area was part of several kingdoms of Upper Macedonia, including the ancient Eordaia and Elimiotis, and it was later part of the kingdom of Macedonia. After the Third Macedonian War it was ruled by the Roman Empire. It later became a part of the Byzantine Empire after the breakup into the West and the East. In the early 14th to the 15th century, it was ruled by the Ottoman Empire and lasted until the Balkan Wars of 1913. The Kozani Prefecture was created in 1915 and also included the present Florina, Grevena and the Kastoria regional units. Modern times Refugees from Asia Minor and Pontus during the Greco-Turkish