December brings holiday markets, tree lightings, and seasonal events that increase travel to both Hartsfield-Jackson Atlanta International Airport (ATL) and Logan International Airport (BOS). Atlanta highlights include the Atlanta Ballet's 'The Nutcracker', Centennial Olympic Park holiday lights, and Midtown Atlanta's festive dining; these events can elevate local hotel demand and airport traffic. In Boston, visitors arrive for holiday markets, the Boston Common tree lighting, First Night New Year's celebrations, and nearby historic town events in Salem and Cape Cod. If attending a festival, book flights and lodging early, check event dates, and coordinate ground transport from the airport to event venues.