There are farmlands throughout the west and southwest, with fewer in the northeast, north and along the Axios River valley.

Its climate includes hot Mediterranean summers and cool to mild winters in low-lying areas and plains.

The area that was to become the Thessaloniki regional unit was annexed by Greece in 1912, during the First Balkan War.

Mustafa Kemal Atatürk, founder of modern Turkey, was born in Salonica, the name for the city of Thessaloniki when it was part of the Ottoman Empire.

The Thessaloniki Prefecture (Greek: Νομός Θεσσαλονίκης) was created when the area was annexed by Greece during the First Balkan War in 1913.