An enclosed waiting space (left) with air conditioning on the Keio line train platform.
Our last sojourn to Costco occurred in the humidity of the rainy season in June. The trip takes about 5.5 hours round-trip and requires a fair amount of train riding and some transfers. My husband and I were gratified to find the enclosed waiting spaces on the platform were air conditioned. They offered very welcome relief from the oppressive heat and densely humid air. They're also good for people who find the winter chill too much for them in the colder months.
I'll miss these comfortable and convenient waiting areas that act as oases of luxurious comfort on (some of) the open train platforms.