if anything i would book soon!!! I looked yesterday...sept is running around 400 USD (n/s ewr-sdq) in November the same flight is approx $1,000 USD (YIKES!!!) this is air fare only. THings are only going to get worse by summers end (they say). Already my friend cant find a direct flight to San Juan
PR in Oct.
November is a roll of the dice for weather. Should be fine...but it IS hurricane season still...and my friends were stuck in their hotel for 5 or 6 days last november when a tropical storm hit. (if you are doing an AI you might want to get vaca insurance...not sure how that works)
I've gone different times of year. Avoid major holidays (xmas, easter new years). For some reason i always find good deals durring high season (feb-mar)
I have also had some luck booking the day before...especialy around 9pm EST. I have found fares for 220 (after taxes and fees) this way...but you have to be ready to go the next day.
again..i am not an AI traveler...so i am not sure if the same tips work.