In Croatia, Hemm families are Croats (from Osijek ).
Prevalence
Only a few people with faimily name Hemm live in Croatia today, in one household only. They are located in one Croatian city only, in Osijek (<5).
Outside Croatia
Family name Hemm (including: Themm , Chemm ) is present in 20 countries worldwide. The family name "Hemm " is used by some 600 people in Germany , about 600 in the United States , and some 60 people in Canada. "Themm " is used by some 200 people in the United States.
In the sources analysed in the project Acta Croatica so far, the name is mentioned few times, the first time 1926 in source Emigration Commission Zagreb.