Benchmarked strictly across TripTiming's 5 empirical pillars: Crowds, Weather, Vibes, Prices, and Safety.
While Mykonos captures an advantage on pure Weather (66 vs 65) with 15°C ambient temperatures, Santorini decisively captures December on Crowds (68 vs 68) and Prices (86 vs 87). Mykonos suffers from seasonal congestion and peak lodging premiums ($114/night), whereas Santorini delivers a more balanced, friction-free itinerary with approximately $105 in lodging savings on a 7-night stay ($99/night vs $114/night).