Japan in May is a "tale of two halves": it is arguably the most crowded time of the year during the first week, and one of the best, least-crowded times for the remaining three weeks. The first week of May coincides with "Golden Week," a series of four national holidays where the entire Japanese population travels simultaneously. During this time, hotels are at 200% capacity, Shinkansen trains are booked months in advance, and popular sites like Kyoto’s Kiyomizu-dera are virtually impassable. However, immediately after Golden Week ends (usually around May 6th or 7th), the crowds vanish, and the weather becomes the "sweet spot" of the Japanese year—mild, sunny, and before the "Tsuyu" rainy season begins in June. In 2026, savvy travelers aim for the mid-to-late May window to enjoy the "lush green" (Shinryoku) season and the blooming azaleas without the overwhelming influx of domestic tourists. If you must visit during Golden Week, you should book your "JR Pass" seat reservations and dinner spots as early as legally possible and be prepared for a "high-density" social experience unlike any other in the world.