Seasons in Japan
Storm season runs August to October
Japan is in its storm season right now, August to October. Most trips are unaffected, but a storm reroutes flights and closes beaches at a day's notice — the packing consequence is a buffer day and a charged power bank, not different clothes.
Going in June
Tsuyu, the rainy season: several weeks of grey, humid, persistent rain across most of the country.
What this means for your bag
A packable rain shell
Not a winter coat — it stays warm through the rain. A light hooded shell that folds into its own pocket ends up in the day bag instead of the hotel room.
See the Weather Protection packQuick-dry fabrics
Cotton takes two days to dry in this air and starts to smell before it does. Synthetics and merino wash in a sink and are wearable by morning.
See the Summer Sun Kit packRoom for humidity
Everything stays slightly damp. Pack fewer clothes and plan to wash them, and keep anything that must stay dry in a sealed bag.
See the Summer Sun Kit pack
Build a packing plan around the season you are actually travelling in.