Ukko

Ukko, 'the old man', is the Finnish thunder and weather god, whose thunder and rain fertilise the fields; his weapons are the hammer and the axe, and a thunderstorm is still ukonilma, 'Ukko's weather'. Unto Salo derives him from the older Finnic sky god Ilmari, with strong Indo-European influence in the figure of Thor, and the name Ukko also serves in the runic songs as a general epithet for several gods. He is the sky god of the Kalevala, where the singer prays to him and he answers with weather, and he is the Finnish god whose cult is best attested in the incantations and in the later harvest customs.

Ukko is addressed outdoors, in plain words, before weather that matters: the first thunder of spring, a field that needs rain, a harvest that needs a dry week. The offering is beer, bread and grain, and the practice has no image - the thunder itself is the sign.