According to the Japanese weather service, typhoon Khanun was "very strong" and delivered maximum sustained wind speeds of 180 km/h (112 mph).
Early on Wednesday, Okinawa's power utility reported that 220,580 houses, or about 35 percent of all households in the area, were without electricity.
Over 690,000 people were advised to leave their homes under an evacuation notice that included Okinawa and the southern half of the Kagoshima area, according to the Fire and Disaster Management Agency.
According to the organization, 11 people in Okinawa suffered minor injuries.
On Tuesday night, national broadcaster NHK said that a 90-year-old man was killed after becoming trapped beneath a collapsed garage. It added that it was likely caused by severe winds.
On the main island of Okinawa, the Japan Meteorological Agency issued a flood and landslip warning.
According to the JMA, the typhoon was about 70 km south of the isolated Kumejima island in Okinawa at 2300 GMT and was heading west-northwest.
Later in the week, it was predicted to go to eastern China.
According to NHK, more than 400 flights were canceled on Wednesday, displacing more than 65,000 people.
Extreme weather events and protracted heat waves have affected millions of people recently all over the world, and experts believe that climate change is making these disasters worse.
Additionally, the Beijing Meteorological Service reported that, since municipal officials began keeping statistics, the capital just had its "heaviest rainfall in 140 years."
The agency said that the highest volume previously recorded was 609 millimeters in 1891. "The maximum amount of rainfall recorded during this storm, which was 744.8 millimeters, occurred at the Wangjiayuan Reservoir in Changping," it added.
According to official broadcaster CCTV on Tuesday, at least 11 people have perished in Beijing's rainstorms, and more than a dozen are still missing.
On Wednesday, the flooding's focal point switched to the nearby province of Hebei.
An AFP crew in Beijing's Fangshan district, which is on the border between the capital and Hebei, observed a park that was entirely submerged, and large amounts of trash that had been swept away by violent rains remained close to a bridge.
A police officer said that the area had been "extremely dangerous" on Tuesday.
On its journey back from the worst-affected areas, a military truck with caterpillar wheels was also spotted by journalists.
Additionally, AFP observed an ambulance, a rescue boat, and a police vehicle traveling the other way towards Zhuozhou, a badly affected Hebei neighborhood.
Inflatable rafts were being rowed by rescuers through flooded districts as residents clung to building scaffolding in anticipation of assistance, according to a state TV video.
Former super typhoon Storm Doksuri, which last week tore across the Philippines, then moved northward over China after making landfall in southern Fujian province.
The amount recorded in just 40 hours neared the average rainfall for the entire month of July.
State media warned last week that 130 million people would be affected by the extremely heavy rainfall across northern China.