Benchmarked strictly across TripTiming's 5 empirical pillars: Crowds, Weather, Vibes, Prices, and Safety.
Seoul emerges as the optimal May destination with an overall TripTiming Index of 66/100 vs 50/100 for Tokyo (+16 point advantage). Seoul captures optimal environmental comfort with 18°C daytime feels-like temperatures and 12% rain probability, compared to 20°C in Tokyo. In addition, Seoul offers more breathing room at premier cultural landmarks (36/100 vs 22/100). Travelers also benefit from lower accommodation costs (~$260/night vs ~$319/night in Tokyo, saving ~$413 over a week). While Tokyo retains an edge in Price & Value (55/100 vs 45/100), Seoul's commanding performance in Weather Comfort secures the overall May recommendation.