Seeing as how Donald Trump has lied about it not raining when it had been, of course there's no chance I'd trust his word on anything. However, many folks, quite reasonably, do expect that the President of the United States should have the most currently available information about a catastrophic hurricane heading towards our country. That's a wee bit bigger of an issue than rain, don't you think? Donald made the choice to tweet about the hurricane. He made the choice to not bother to be attentive to the facts, to be careless. To then compound his wrong by insisting it was right when it wasn't.
Since you want to bring up President Obama so bad, look at how he conducted himself during the hurricanes that happened during his terms. He never gave wrong information then had himself a giant tempter tantrum insisting that the wrong info was right.