The seasons may matter a tiny bit and you can read about that here: https://www.genderdreaming.com/forum...s-swaying.html I would not personally hold off for that reason, swaying matters far more, this is just a few percentage points. I got my daughter in the boy peak months and 2 boys in the girl peak so that shows you about how well it works. :)
It is not temperature that matters, it's probably something to do with day length. if the temperature mattered the peak would be in wintertime. Another site claims winter sways blue but that is not based on science at all, unlike the seasonal peak we're referring to, which is based on a couple of very well done studies.
Length on diet matters by far and away more than seasons. We don't even know how seasons work, and since I think the evidence indicates it is probably day length and not temperature, it would be a step in the wrong direction to shortchange yourself on diet (which we KNOW time on diet matters because we've seen it in our results) in favor of a theory which we are guessing as to how it works.
Exercise is one of our best sway tactics but given your low weight you'll need to boost food intake to compensate. :)