This is not good Summer Olympics weather

This is a great time of year to NOT be an Olympic athlete. It is just way too humid.

Although the Tokyo Olympic organizers claimed they’d provide a place “where athletes can perform at their best," that was ... less than true, as the finish line of the triathlon showed.
"I have been to Manila, Bangkok, Jakarta, Phnom Penh and Singapore in mid-summer and in my experience Tokyo is the worst of them all,” said Robert Whiting, author of numerous books about Japan. [Source]

The last time Tokyo hosted the Summer Games was October 1964. That kind of timing would have avoided these kinds of conditions, but no -- somebody decided the Summer Games had to actually be in summer.

The Paris Olympics in 2024 are scheduled to be in the same time frame. My guess is that it has something to do with the schedules of other sporting events.