To be honest, I have no idea what the writer is trying to say. Even if you ignore the mistake in the first half - "It getting" instead of "It is getting" - there is still a mismatch of tenses between the two phrases and no logical connection. "The food is sold well" is a particularly strange. This is not a very meaningful phrase for a native speaker. I suspect that this sentence was written by a non-native. It isn't quite right, and it certainly isn't worth worrying about. Forget about it.

according to my understanding of this sentence, number 2 is more close to the question. the weather is getting warmer is the reason to the result of the food is sold well. wish it helps.