Simplify the following text for a Grade 5 native English-speaking person.
Original: The Babylonian constellation was sacred to Adad , the god of rain and storm ; in the second Millennium it would have risen just before the start of the autumnal rainy season .
Simplified: Adad was the god of rain and storms . In the time of the Babylonians , the constellation would have risen just before the start of the autum rainy season .