Typhoon No. 20 was approaching Japan's main island Honshu on the morning of Oct. 21, the Japan Meteorological Agency said.

The agency warned people in areas that suffered damage from recent Typhoon No. 19 to take safety precautions, saying that even a small amount of rain can raise the risk of flooding in devastated areas.

By Oct. 22, the typhoon will likely be downgraded to an extratropical cyclone when it arrives in the sea south of Honshu, the agency said. But it will continue moving north with a stationary front.

Wide regions from western Japan to northeastern Tohoku may experience heavy rainfall from Oct. 21 to 23.

Heavy rain may hit areas stretching from Japan's southern island Shikoku to eastern Japan between Oct. 21 and 22, and in the Tohoku region between Oct. 22 and 23.

Typhoon No. 21 is also moving northward from the sea south of Japan. It is expected to become an extratropical cyclone in waters near the Kanto region on Oct. 26.