[1] On July 14 at 02:30 UTC, the Joint Typhoon Warning Center (JTWC) began monitoring an area of convection that had originated from a non-tropical low as it was located approximately 420 nautical miles (780 km; 485 mi) north-northeast of Guam.

[9] The low-level circulation continued to consolidate,[10] and at 12:00 UTC, Khanun entered the Philippine Area of Responsibility (PAR), with the PAGASA giving it the local name Enteng.

[12] Khanun continued to organize, and at 15:00 UTC, the JTWC upgraded it to a tropical storm as it was located approximately 370 nautical miles (685 km; 425 mi) east-northeast of Kadena Air Base.

[13] A weak eye feature appeared on microwave imagery,[14] and on July 17 at 11:00 UTC, Khanun made its closest approach to Okinawa, passing within 85 nautical miles (155 km; 100 mi) of the island.

[15] Khanun peaked in intensity at 18:00 UTC, with maximum sustained winds of 95 kilometres per hour (60 mph) and a minimum central pressure of 985 hPa (mbar; 29.09 inHg).

North Korea's official media reported that premier Choe Yong Rim visited flooded towns and discussed ways to help recovery efforts.

On 4 August, government sources announced the death toll from both Khanun and the torrential rains in late July had risen to 169, with around 400 others missing.