Due to multiple factors, expect to potentially pay more when booking in December. For low rates, September can be a great choice for travel to Queretaro. Flights to Queretaro from Syracuse in September are about $454 on average during September, but can be found for as low as $178.
Regardless of the time of day you decide to fly, the ticket price will remain around the same. Book flights from Syracuse to Queretaro as you normally would.