The JTWC identified a tropical depression near the Caroline Islands late on August 4 UTC. The JMA designated it as such at 12 a.m. UTC August 5. Nine hours later, the JTWC upgraded Tropical Depression 08W to a tropical storm, three hours before the JMA named it Saomai. The name is from the Vietnamese "sao Mai", meaning "Morning Star",[12] a reference to the planet Venus.

The JTWC designated it a typhoon at 3 p.m. UTC August 6. The JMA upgraded Saomai to a Severe Tropical Storm at 6 p.m. UTC, and as it continued to strengthen, it was upgraded to a typhoon just 12 hours later. Saomai passed into the Area of Responsibility of PAGASA on August 8 and was named Typhoon Juan by PAGASA. On August 8, the storm underwent explosive development, and by August 9 it had become a Category 5-equivalent super typhoon.

Saomai made landfall in Zhejiang, China on August 10 with maximum sustained winds of 115 knots (1-minute mean), stronger than Chanchu earlier this season. Saomai was responsible for at least 458 deaths, mostly in China, and $2.5 billion (2006 USD) in damage.