Family name Sumor (Summer 
, Sumor 
) , across the world, is a common surname. The surname Sumor is characteristic of Austria, where it is quite a common surname, Macao, where it is quite a rare surname, and Brunei. Not in comparison with a country's population, it is commonest in the United States, China, and Austria. More prevalently, Sumor is the forename as well as the last name.