Rowing and archery events have been moved due to the storm which is expected to head over Japan's northeast coast on Tuesday and could bring heavy rain to the capital.

Rowing races were rescheduled for later in the week, while Monday's events were move to Sunday in anticipation of the storm.

"At this time there are no plans to change the schedule for any of the other events due to be held on Tuesday," Tokyo 2020 spokesman Masa Takaya told reporters on Monday.

The likely wind and rain will follow intense heat, which has caused one Olympic archer to collapse and had skateboarders complaining of unbearable conditions by 9am.

The rain also threatens Tuesday's two medal games for softball. Canada, vying for bronze, said their flights home are scheduled for Wednesday with the next available potentially not until Saturday because the pandemic has limited options.

But their accommodation needs to be taken over by newly arriving athletes sooner.

"We very much hope the game goes on tomorrow," coach Mark Smith said.

"We don't have a lot of flexibility."

Postponement would give athletes recovery time after five games in six steaming days, but Canada pitcher Danielle Lawrie said she could do without.

"When you're in the last four teams standing, you're running on some adrenaline," she said.

"Once you get warmed up and ready for battle, you forget how all of that feels."

The storm is forecast to pass to the north of Tokyo, according to the Japan Meteorological Agency.

Australian Associated Press