Please advise which of the following is correct:

It rained heavy / heavily yesterday.

New Member20
We need an adverb here, so the answer is heavily.
Regular Member749
Moderator: A super-user who takes care of the forums. You have the ability to message a moderator privately should you wish. These users have a range of elevated privileges including the deletion, editing and movement of posts when needed.Proficient Speaker: Users in this role are known to maintain an excellent grasp of the English language. You can only be promoted to this role by the Englishforums team.
It rained heavily yesterday.
Junior Member73