Benchmarked strictly across TripTiming's 5 empirical pillars: Crowds, Weather, Vibes, Prices, and Safety.
Cancun decisively leads San Juan in May across both environmental comfort and space tranquility. With a composite index advantage of +5 points, Cancun delivers superior sightseeing conditions (36°C feels-like, 18% rain probability) while avoiding the heavier tourist footfall and queue friction observed in San Juan.