Where does “ukkostaminen” come from?

ukkostaminen (Finnish) comes from Finnish ukkostaa, from Finnish ukkonen, from Finnish -nen, from Finnish -inen, from Finnish -uus, from Proto-Finnic -uc — -ness, -hood.

Ancestry of “ukkostaminen”, step by step

Step	Language	Word	Meaning
1	Finnish	ukkostaa	to thunder
2	Finnish	ukkonen	thunder; thunderstorm
3	Finnish	-nen	Forms diminutives nouns or terms expressing...
4	Finnish	-inen	-like, -ous, -y; -en; Creates adjectives from...
5	Finnish	-uus	Forms nouns from adjectives, expressing a quality
6	Proto-Finnic	-uc	-ness, -hood

Every word from Proto-Finnic -uc →Every word from Finnish -inen →Every word from Finnish -uus →