Japan is one of the world’s most typhoon-prone countries. Each year, roughly 5 to 10 typhoons make landfall or pass close enough to cause significant disruption to daily life. For foreigners new to Japan, typhoon season can be alarming — especially the first time. This guide explains what to expect, how to prepare, and how to stay safe.

When Is Typhoon Season?

Typhoon season in Japan runs roughly from June through October, with the most intense and frequent storms occurring in August and September. Okinawa and Kyushu face the most direct hits, but typhoons regularly affect Shikoku, the Kinki region (Osaka, Kyoto), and even the Kanto area (Tokyo).

What Is a Typhoon?

A typhoon is the same phenomenon as a hurricane or cyclone — a tropical storm system with sustained winds and heavy rainfall. In Japan:

  • Strong typhoons (Category 3+ equivalent) bring winds over 120 km/h, extreme rainfall, flooding, and storm surge at coastal areas
  • Weaker typhoons and tropical storms still cause significant rainfall and wind damage, flooding of rivers, and transport disruption

Even a typhoon that doesn’t make direct landfall can drench a region with torrential rain for 24–48 hours.

How Japan Warns About Typhoons

The Japan Meteorological Agency (JMA) is the authoritative source for typhoon information. Key alert levels:

Special Warnings and Advisories

  • Typhoon Warning (台風警報): Issued when damaging conditions are expected within 24 hours
  • Typhoon Advisory (台風注意報): Lighter conditions expected
  • Emergency Warning (特別警報): Issued rarely for extreme events; highest alert

Alert Levels for Evacuation (Keikai Level)

Local municipalities issue evacuation orders on a 1–5 scale:

  • Level 3: Elderly and vulnerable people should evacuate
  • Level 4: Everyone in the danger zone should evacuate
  • Level 5: Disaster is already occurring — evacuate immediately if safe to do so

These alerts are broadcast on TV, municipal PA systems (outdoor speakers), and pushed via the Yahoo! Japan Weather app, NHK Weather, and the J-Alert system (sent automatically to mobile phones).

Building Your Emergency Kit (Hijonin Bā)

The Japanese government recommends keeping a disaster bag (非常用持ち出し袋, hijonin mochi-dashi bukuro) ready at all times. For typhoons, prepare at least 3 days of supplies:

Essential supplies:

  • Water: 2 liters per person per day (minimum 3 days)
  • Non-perishable food: canned goods, instant rice, energy bars
  • Portable phone charger (power bank)
  • Flashlight and spare batteries
  • First aid kit
  • Cash (ATMs and payment systems may be down)
  • Copies of important documents: passport, residence card, insurance card
  • Medications (at least one week’s supply)
  • Rain gear

For extended evacuation:

  • Change of clothes
  • Blanket or emergency thermal sheet
  • Radio (battery-powered or hand-crank)
  • Whistle (for attracting attention)
  • Masks and sanitizer

Before a Typhoon Hits

When a major typhoon is forecast 24–48 hours out:

  1. Check the path: JMA, NHK Weather, and Windy.com show projected paths
  2. Stock supplies: Buy water, food, and batteries before stores empty (they will)
  3. Secure outdoor items: Balcony furniture, bicycles, and loose objects should be brought inside or tied down
  4. Charge devices: Charge all phones, laptops, and power banks
  5. Know your evacuation point: Your ward office’s hazard map (available free at the office and online) shows local evacuation shelters (避難所, hinanjo)
  6. Check transport: Trains typically suspend service ahead of major storms — plan accordingly

During the Typhoon

  • Stay indoors: Do not go outside during the storm unless evacuating
  • Avoid rivers and low areas: Flash flooding and river overflow are common causes of death
  • Stay away from windows: Tape or shutters help; better to be in an interior room
  • If you lose power: Use flashlights (not candles), keep refrigerator and freezer closed
  • Follow evacuation orders: If Level 4 or Level 5 is issued for your area, go to the designated shelter

After the Typhoon

  • Do not immediately venture out — winds can remain dangerous hours after the eye passes
  • Check for flooding before using basements or lower floors
  • Avoid driving through flooded roads
  • Report damage to your ward office or emergency services
  • Check for utility outages — report gas leaks to the gas company immediately

Apps and Information Sources in English

  • NHK World: English-language disaster information
  • Yahoo! Japan Disaster Prevention (Yahoo!防災速報): Push alerts — Japanese but with images
  • Japan Safe Travel: English-language emergency information portal
  • Tokyo Metropolitan Government Disaster Map: Downloadable hazard maps for Tokyo wards