Living in Japan

Preparing for the Typhoon Season in Japan

The typhoon season in Japan runs from June 1st to November 30th, although most storms will develop in July through October. Below are tips for how to stay informed and how to prepare as a typhoon approaches.

What is a typhoon?

A typhoon is a tropical storm that occurs in the region of the Indian or western Pacific oceans.

Once a storm system’s maximum sustained winds reach wind speeds of 64 knots (74 mph; 119 km/h), the Japan Meteorological Agency will designate a tropical cyclone as a typhoon, which is the highest category on its scale.

This map shows the tracks of all tropical cyclones in the 2017 Pacific typhoon season.  Image: Wikimedia

According to the Japan Meteorological Agency, there was an average of 26.7 typhoons a year between 1971 and 2000, with 10.8 of them reaching within 300 km of the Japanese archipelago. During this time span, an average of 2.6 typhoons made landfall annually. Typhoons later in the season tend to be stronger than typhoons earlier in the season.

Typhoons are extremely powerful. Studies show that the energy unleashed by an average typhoon can reach a force 100 times greater than that generated by the atomic bomb dropped on Hiroshima. However, the force of typhoons usually diminishes through friction with sea or land surfaces, and is also influenced by temperatures and wind force in the surrounding atmosphere.

Typhoons are dangerous not only because of high wind speeds. Many deaths in typhoons are caused by flooding and landslides.

Typhoon Noru, which made landfall on Wakayama prefecture on August 7, 2017, was the second longest lasting tropical cyclone of the Northwest Pacific Ocean on record. Noru was responsible for two deaths in Kagoshima Prefecture and caused at least $100 million in damage in Japan.

General Preparations (Far in Advance)

1. Get the outside of your house in order

If you live in a single-family home, make sure that your roof gutters are clear. Also, inspect the the roof and walls of your home, as well as any surrounding fences to make sure they’re structurally sound.

2. Stock up on emergency supplies

Your emergency kit should include the following, which is applicable to any natural disaster, not just a major typhoon.

  • A battery-powered flashlight and back-up batteries
  • Change of clothes and a towel
  • Lighter and matches
  • Emergency medicines and a first aid kit
  • Portable radio
  • Valuable personal items
  • Small change (including 10-yen coins that can be used at a public phone)
  • Emergency food supply
  • Water

3. Decide on a family meeting point

If you are living in Japan with your family, discuss with them where you will all meet in case of an emergency and how you will contact each other. In a major disaster, local cell phone service may be disrupted, but it may still be possible to make long distance calls (and leave a message with a friend or relative in a location far from your home or work place). Practice walking your evacuation route beforehand by yourself and with your children.

4. Get a copy of your local hazard map

A hazard map is a map prepared by local municipalities in Japan that outlines the estimated risk from tsunami, flooding, landslides, and liquefaction, etc so that the public can understand and better prepare for a potential natural disaster in their area.

Many municipalities have English versions of hazard maps. You can go to your city, town, or ward office (or their website) to get a copy. In addition to showing the risk of various areas, the map will also show the location of emergency evacuation centers and meeting points.

Sample page of the English version of the flood hazard map prepared by Ibaraki City. The map shows the depth of flooding expected by the overflow of the Ai River for specific neighborhoods. Image: Ibaraki City Hazard Map

5. Get to know and communicate with your neighbors

If you have some Japanese ability (or even if you have very little!), it’s a good idea in general to greet and get to know your neighbors. In an emergency, it is often the case that neighbors will be able to help each other before emergency response teams can get to you.

Preparations as a Typhoon Approaches

1. Stay Informed

Japan has one of the world’s leading natural disaster warning systems. The Japan Meteorological Agency provides almost real-time updates to the public to give warnings of imminent natural disasters, including tsunami and typhoon. These advisories and warnings will be broadcast by radio, television, and the internet.

You will have days of advanced warning, as a typhoon approaches, and as it gets closer, there will be more and more information about where it will make land fall and the direction in which it is moving. It’s a good idea to stay on top of this information as it is broadcast.

The English homepage of the Japan Meteorological Agency (JMA) is the official online source of information on weather advisories.

English home page of the Japan Meteorological Agency.

2. Get almost real time weather updates online

This is the JMA’s official information portal in English, where you can get almost real-time weather updates.

Get almost real-time weather updates through the JMA weather advisory portal.

There is also a JMA portal  where you can track typhoons as they approach:

The JMA’s Tropical Cyclone Portal.

3. Lock Down: Close storm windows and tape up windows and secure objects

Many single-family homes in Japan are built with storm windows. If you don’t have storm windows, you can minimize the chance of flying glass by taping up your windows in a crisscross pattern and closing curtains. It’s also good to know that most windows in Japan are made of shatterproof glass.

Take pots, plants, and other objects off of your balcony. Typhoon force winds can be strong enough to blow heavy objects off your balcony or right through a window.

4. Minimize flood damage to your belongings

Minimize flood damage your belongings by moving them off the floor or to the second floor, if you have one.

5. Charge up electronics and secure extra water

Typhoons are dangerous not only because they can cause bodily injury and damage to property. Strong winds can also knock down power lines and disrupt water supply.

Make sure your mobile devices and computer are fully charged. You can also run a bathtub full of water for a large supply of emergency water, in case water supply is interrupted.

One way to keep the contents of your fridge cool in a power black out is to freeze PET bottles of water and use these as ice blocks.

6. If there is a chance you can be stuck outdoors, stay where you are (inside!)

Many companies will let employees leave work early so they will not be caught outdoors or in the subway during a typhoon. If there is a chance that you will be stuck outdoors, stay indoors where you are until the storm passes. This also means that it is a good idea to carry some portable emergency supplies (like water and food) with you at all times.

What to do in the middle of a typhoon

1. Stay indoors

As a typhoon is approaching and in the midst of a typhoon, do not go outside! The danger is not just from high winds, but also flash flooding, landslides and possibly flying objects.

If you are trying to evacuate by car, remember that wipers do not work when there is more than 20-mm of rainfall an hour and that that cars can hydroplane if the tires hit more water than they can scatter.

2. If you are outdoors, don’t go near rivers, canals and the ocean

The JMA advises that people do not go near rivers and canals because in a typhoon, you can easily misjudge the location of a water boundary and be pulled in. The danger from going near the ocean is from a storm surge.

3. Continue to stay informed throughout the storm

Stay tuned to NHK and/or the use the websites mentioned above to keep updated.