Hello!
The Central and Eastern European community is running CEE Spring again this year. It runs till May 31.
CEE Spring is a Wikipedia article contest which aims to cover CEE region in CEE languages. So far more than 4000 articles have been created.
In case you are interested in running a thematic week(s) in your Northern European wiki, please contact me and maybe we can arrange "thank you" postcards for best contributors.
There is also a sub-contest CEE Women where you sign up individually and after completing your challenge you can get a postcard.