For general discussion between ESL teachers.
that could be true Estefania ... even in Europe during summer, the sun sets at 9:30 pm. Of course, if there's a consistent explanation before or after that "It's sunny tonight!" sentence, I think it would be carefully considered. But if the sentence stands there alone without any explanation of how the author came up to that "sunny" thing, well,I don't know...and that's how I believe that we came up to a discussion using grammar rules, that is, if the sentence has general truth.