Akka

Akka or Rauni is the Finnish goddess of fertility. She is the wife of Ukko.

The few sources referring to Ukko's wife are unclear and have thus resulted in multiple theories of their meaning. One interpretation suggests, that Ukko's wife might also have been some form of a thunder god. However, a more common interpretation considers Ukko's wife to be a goddess of fertility. Thunders are caused by the couple either having a fight or making love.

Etymology
"Akka" means "woman" or "wife". In modern Finnish it's often used to refer to "old woman" or "old hag".

"Rauni" name appears in Mikael Agricola's list of Finnish pagan gods from 1551. The list says: "Rauni Ukon Naini" but it is unclear if this translates to "Rauni, wife of Ukko" or "The wife of Rauni-Ukko" (= Rauni would be Ukko's name instead). In Sigfridus Aronus Forsius' Latin translation Ukko creates rains and shoots frightening lightnings, and Rauna moves the winds and also threatens with lightning. The name "Rauni" doesn't appear in Finnish folk poetry, but in a Forest Finnish poem from Värmland, there is a mention of Ryönikkä or Röönikkä, which could refer to Rauni. Assuming that this is the case, Akka would have also been a haltija of rowans. Rowans were sometimes planted on yards in order to protect the buildings from lightning strikes. In Old Norse, raunir means a rowan.