Is it correct to say "The reason is because ..."?

In a statement like

The weeds have grown overnight. The reason is because it rained yesterday

Is "the reason is because" good grammar? Isn't it better to say

The weeds have grown overnight because it rained yesterday

The second form seems simpler and the words the reason is seem to add nothing to the sentence. Is there any technical reason to avoid the longer form?

Solution 1:

"The reason is because..." is wrong; the other one is the one to go with.

That "the reason" is already explaining why, i.e. the reason, so putting also because will create a sort of redundancy.

See this article, which goes more in depth.

Solution 2:

I am going to disagree with both other answers here. I don't think there is anything grammatically wrong with either of the sentences:

The reason is because it rained yesterday.
The reason is that it rained yesterday.

I agree that this sentence sounds a lot better with that, in part because because is redundant. But consider:

The only good reason to go to graduate school in English literature is because you love it.
The only good reason to go to graduate school in English literature is that you love it.

The reason he faked his suicide and went into hiding in Peoria using a fake name is because his life was in danger.
The reason he faked his suicide and went into hiding in Peoria using a fake name is that his life was in danger.

In these cases, I think because sounds superior to that. But don't these sentences have exactly the same grammatical structure? So how can the first one be ungrammatical and the other two grammatical? I think the reason because sounds better now is that there is a large gap between reason and because, which means that now the redundancy becomes useful rather than superfluous.

Let me add that the Merriam-Webster dictionary agrees with me. From the conclusion of their long discussion at the above link:

In sum, "the reason is because" has been attested in literary use for centuries. If you aren't comfortable using the phrase, or feel that it's awkward, don't use it. But maybe lay off the criticism of others—there's really no argument against it. The phrase may grate on your nerves (along with "the reason why is because"), but it puts people who apply it in some very distinguished literary company.