The word "typhoon" is derived from the Chinese word tai feng. Typhoons are tropical storms in the Pacific Ocean but only west of the International Date Line. Storms east of that are called hurricanes.
Taiwan's Central Weather Bureau classifies typhoons into three categories. The lowest category, "tropical storm", refers to a system with wind speeds of 32.6 m/s or less. Moderate typhoons have wind speeds between 32.7 m/s and 50.9 m/s, and anything greater than that is classified as a strong typhoon. In media reports and daily conversation, the terms "violent typhoon" and "super typhoon" are often thrown about, but they are not used in official classification methods.
On average, three to four typhoons visit Taiwan every summer. The heavy rains and strong winds brought by typhoons often cause flash floods and landslides. As a result, it is common practice for local governments to announce the cancellation of work and school to ensure the public's safety. These announcements can come as late as halfway through the day, depending on conditions.
With destructive winds and unrelenting rain, typhoons can damage local infrastructure, often causing localized power outages and interrupting water supplies. Heavy flooding can cause schools and other organizations to close down for weeks while excess water is pumped out and safety checks are run.
When two typhoons are coming together, they may interact with each other and cause the so-called “Fujiwara Effect”. The interaction will eventually lead to the two typhoons merging and unleash massive disasters.
The most devastating typhoon to hit Taiwan in recorded history occurred in 2009. Typhoon Morakot left nearly 800 people dead and US$6.2 billion in damages. Landslides and floods were responsible for most of the deaths, including one village that was reportedly completely covered in a mudslide.