Three hymns of the Rigveda are addressed to Parjanya and almost everything the tradition has to say about him is inside them. He is the rain, and the poets do not separate the god from the weather: the same word names the cloud, the water that falls out of it and the power that sends it, and a verse can move between the three without marking the change. The imagery is agricultural and frankly sexual. Parjanya is a bull who bellows, and the bellowing is thunder. He deposits the seed in the plants. The winds break loose, the lightning falls, the herbs shoot up, and the earth is described as bowing under him. One hymn asks him to rain and then, having got what it asked for, asks him to stop.
What makes him unusual in the Rigvedic pantheon is that he is not a warrior. Indra also brings rain, but he brings it by killing something, and the release of the waters is the consequence of a victory. Parjanya simply rains. The hymns to him contain no combat, no enemy and no weapon, and their concern is the ordinary anxiety of people who grow things and keep cattle: whether the rain will come, whether it will come at the right time, and whether it will stop before it does damage. That gives this small group of hymns a domestic register the rest of the collection largely lacks.
He is also one of the clearest points of contact between Vedic religion and its Indo-European relatives. The name has been set beside the Baltic Perkunas and the Slavic Perun since the nineteenth century, and beside the wider family of thunder gods whose names are built on the same consonants. The comparison is standard and it is not settled, because the Vedic figure is closer to rain than to thunder, and the sound correspondences have been argued over for as long as the comparison has existed.