Being also the tenth named storm and this season's fifth typhoon, Haishen's origins can be tracked back to a disorganised low pressure area situated near Guam.

Drifting northwestward into extremely favorable conditions, Haishen became a category 3-equivalent typhoon, acquiring a pinhole eye, before undergoing an eyewall replacement cycle (EWRC).

Strengthening resumed soon after and the JTWC assessed wind speeds of 135 kn (155 mph; 250 km/h) as it peaked as a powerful Category 4 super typhoon and had attained a new, symmetrical, clear eye.

The eye's former shape was no longer present as it appeared ragged on satellite imagery, and Dvorak analysis indicated that Haishen was beginning to weaken steadily.

On August 29, the JTWC began tracking a very disorganized tropical disturbance situated a couple hundred miles northeast of Guam.

By the next day, the disturbance had quickly organized, and the JTWC issued a Tropical Cyclone Formation Alert (TCFA) for the low-pressure area.

Intensification on September 3 was significant - with Typhoon Haishen acquiring a pinhole eye early in the day, but it later underwent an eyewall replacement cycle.

[3][4] Early on September 4, the JTWC assessed that Haishen became a Category 4-equivalent super typhoon - with 1-minute sustained wind speeds of 135 kn (155 mph; 250 km/h),[5] with a clear, symmetrical eye visible on satellite imagery.

[6] On September 5, as Haishen's latitude increased, the ocean heat content in the area decreased,[10] which disrupted the system's core and caused its eye to appear ragged on satellite imagery, subsequently indicating weakening, and dropping below super typhoon status.

[8] Haishen made landfall in Ulsan, South Korea at around 09:00 KST (00:00 UTC) on September 7,[12] with 10-minute maximum sustained winds at 140 km/h (85 mph) and the central pressure at 955 hPa (28.20 inHg).

Shortly after, Haishen entered the Sea of Japan as a high-end tropical storm; due to the low-sea surface temperatures, Haishen quickly weakened and made landfall in the South Hamgyong Province, North Korea with 10-minute maximum sustained winds of 100 km/h (60 mph) and a central pressure of 980 hPa (28.94 inHg).

[23] As of being in the path of Haishen, the Japanese Coast Guard was forced to temporarily suspend their search and rescue mission for missing crew members of the cargo ship, Gulf Livestock 1, which sank a week before as of the effects of Typhoon Maysak.

[22] In Busan, a city with a population of 3.4 million, traffic lights collapsed, signboards were ripped off and roads shut down due to strong winds and heavy rain.