Due to multiple factors, expect to potentially pay more when booking in January. For low rates, September can be a great choice for travel to Ponce. Flights to Ponce from Atlantic City in September are about $429 on average during September, but can be found for as low as $238.
Regardless of the time of day you decide to fly, the ticket price will remain around the same. Book flights from Atlantic City to Ponce as you normally would.