Mette is also Dutch (evidence for this can be seen on the popularity chart for the Netherlands) and Finnish. The name day for Mette in Finland is March 15.
This is a very, very common name in Denmark. A lot of girls in my baby sisters´ school classes are called Mette. A little boring name, but it's nice that it means "pearl".
Also Finnish:
https://www.behindthename.com/name/mette/top/finland
https://www.nordicnames.de/wiki/Mette