nac
Hi Daniel,
I arrived at NAC in Sept 04, and oh boy is it warm in Sept! I'd say that it must have been close to 100% with extreme humidity which is the killer!
Can't really comment on the PPL timescales as I already had it before I came, but I do know of people that have completed it in 3-4 weeks. The time of year that you mention is however the hurricane season, which can sometimes (and did last year) delay your progress by robbing you of a few days flying.
My best bit of advice to you would be to get all of your written exams completed before arriving here as that is what can delay people the most. Doing it that way will ensure that you can concentrate solely on your flying.
Good Luck
ADRH