Typhoon Season in Japan 2026: The Warning System Just Changed (What Level 3 and Level 4 Really Mean)

This article contains promotional / affiliate links.

If you are in Japan between August and October, you will almost certainly experience at least one typhoon. And in 2026, there is something new you need to know: Japan changed its entire disaster warning system on 29 May 2026. Almost every English-language typhoon guide online is now out of date.

This guide covers what actually changed, how to read the new warnings, what to do at each level, and how typhoons affect trains, flights, and daily life as a foreign resident or traveller in Japan.

2026 typhoon season: what forecasters expect

The Japan Weather Association (JWA) published its 2026 typhoon outlook in May. The key points:

August is the peak risk month this year. JWA forecasts the number of typhoons approaching Japan will be average to above average, centred on August. This is linked to a weakening of the Pacific High over Honshu, which allows typhoons to track north toward Japan more easily.

Autumn typhoons may be stronger. Japan is likely to shift into an El Niño pattern. When that happens, typhoons tend to form further southeast, further from Japan. That means they spend longer over open ocean before arriving — and arrive more fully developed. Fewer storms, but potentially more powerful ones.

The season has already been unusual. According to the Japan Meteorological Agency (JMA) typhoon records, Typhoon No. 6 made landfall in May 2026 — remarkably early — and Typhoons No. 7, 8 and 9 approached Japan in June and July. By the end of July, 12 typhoons had already formed.

The big change: Japan’s new warning system (from 29 May 2026)

This is the single most important thing to understand this year.

What was wrong with the old system

Previously, Japan issued warnings with names like “Heavy Rain Warning”, “Landslide Alert” and “Flood Danger Information”. Japan also has a separate 5-level alert scale for evacuation. The problem: it was not obvious which warning corresponded to which level. Even Japanese residents regularly misjudged whether a warning meant “pay attention” or “leave now”.

What changed

From 29 May 2026, the alert level number is built into the name of the warning itself. What used to be called a “Heavy Rain Warning” is now called a “Level 3 Heavy Rain Warning”. You hear the name, you know the action.

JMA also introduced a new rapid bulletin designed to give earlier notice of senjo kosuitai (linear rainbands) — the stalled bands of extreme rainfall responsible for many of Japan’s deadliest recent flood disasters.

The 5 alert levels and what you should actually do

The most common and most dangerous mistake is waiting for Level 5. Level 5 means the disaster is already happening. Level 4 is the last point at which evacuation is normally safe — and Japan’s official guidance is explicit that Level 4 means everyone leaves.

There is one more point foreign residents often miss. JMA states that you should not wait for your city to issue an evacuation order. If Level 3 or Level 4 information is published, you can and should judge for yourself using Kikikuru and river water level data.

Kikikuru: the one tool you should bookmark now

Kikikuru (キキクル) is JMA’s real-time danger map. It colour-codes flood, landslide and inundation risk down to a very local level, updated every 10 minutes.

Why it matters for foreigners: it is visual. You do not need to read Japanese to understand it. Black and purple mean the danger is at or beyond the level where evacuation should already have happened. Red means Level 4 equivalent. Yellow means Level 3 equivalent.

Bookmark it on your phone home screen before a typhoon arrives. Searching for it while the wind is howling is not the plan you want.

Also worth having: the NHK World app and Safety Tips (the government-backed multilingual disaster alert app for visitors), plus your local city’s disaster prevention page.

What actually happens during a typhoon in Japan

Trains: planned suspensions (keikakuteki unkyu)

This surprises almost every newcomer. Japanese railways now announce planned suspensions in advance — often the day before. JR East, JR West, and private lines will state something like “trains will stop from 12:00 tomorrow”.

Two implications. First, the trains stop before the weather looks bad. Do not assume you can leave later. Second, they do not restart immediately after the storm passes; safety inspections take hours. A typhoon that passes overnight can still mean no trains until midday.

Flights: cancelled early and in bulk

ANA and JAL typically announce cancellations 24 hours ahead. If your flight is cancelled due to weather, you are normally entitled to a refund or free rebooking — but airlines are not obliged to cover your hotel, since weather is outside their control. Rebook online immediately rather than queueing at the airport.

Shops, offices and konbini

Many companies now declare work-from-home or closure in advance. Convenience stores usually stay open but sell out of bread, onigiri, water and batteries within hours. Deliveries stop, so restocking may not happen for a day or more.

Power cuts

This is the most likely typhoon impact by far. Flooding is geographically limited; power cuts are not. If you live in a modern all-electric apartment, a blackout means no cooking, no hot water, and no elevator.

Your typhoon checklist: 72 hours to landfall

That last point is worth repeating. In Japan, damage compensation and insurance claims depend heavily on documented evidence. Photograph before you tidy. Wide shots, close-ups, and the height of any water line.

Typhoon supplies: what to actually buy in Japan

You can buy nearly everything at a home centre, Don Quijote, or online. Priorities in order:

1. Water and no-cook food. Three litres per person per day, three days minimum. Retort curry, canned food, bread, and instant noodles that can use lukewarm water.

2. A light that does not need one specific battery size. A common failure is owning a torch that takes D batteries when all you have are AAs. Panasonic’s “Any Battery Light” (BF-BM10) runs on a single D, C, AA or AAA cell — and you can mix sizes.

3. A power bank, and ideally a portable power station. A phone power bank is the minimum. If you live in an all-electric building or work from home, a portable power station (EcoFlow, Anker, Jackery) will run a fan, lights and your laptop through a blackout.

4. A radio. When power and mobile data fail, radio still works. Sony’s ICF-B99 runs on batteries, hand crank or solar, and can give your phone a short emergency charge.

5. Cash. Card readers and ATMs stop working in a blackout. Japan is still a country where cash solves problems.

Typhoon vocabulary you will hear on Japanese TV

Frequently asked questions

Is it safe to travel to Japan during typhoon season?

Yes, with planning. Typhoons are forecast days in advance, and Japan’s infrastructure response is excellent. The main risk to travellers is not danger but disruption — cancelled flights and stopped trains. Travel insurance that covers weather delays is strongly recommended if you are visiting between August and October.

Should I go to an evacuation shelter?

Only if you are in a flood, landslide or storm surge risk area — check your hazard map. If you live in a sturdy mid-rise concrete building away from rivers and slopes, staying home on an upper floor is usually safer than travelling through a storm. JMA explicitly advises that you do not need to reach a designated shelter: moving to a higher floor of a nearby solid building is a valid choice.

What if my Japanese is not good enough to understand the alerts?

Use Kikikuru (colour-coded, no reading required), the Safety Tips app (multilingual push alerts), and NHK World. Also tell your building manager or a neighbour that you may need help — Japanese neighbourhood associations often check on residents during disasters.

My flight was cancelled. Who pays?

The airline will refund or rebook you free of charge. Accommodation and meals are generally not covered for weather cancellations, because it is outside the airline’s control. This is what travel insurance is for. Rebook through the app immediately — airport counters get very long queues.

Do I need to tape my windows?

Taping glass does not meaningfully stop it breaking. What helps is closing storm shutters (amado) if your building has them, keeping curtains closed to contain glass if it does break, and staying in a room without large windows during the peak.

How long do power cuts usually last?

Most are restored within hours. However, after major typhoons in recent years, some areas of Chiba and Kyushu were without power for over a week. Plan for 24-72 hours, not for two hours.

The short version

If you remember only three things from this guide:

One. From 29 May 2026, warnings carry their alert level in the name. Level 4 means everyone evacuates. Do not wait for Level 5.

Two. Trains stop before the storm arrives, announced a day ahead, and restart slowly. Plan your movements around the announcement, not the weather.

Three. The most likely thing to happen to you is a power cut. Water, a light that takes any battery, a charged power bank and some cash will cover 90% of what you actually need.

Bookmark Kikikuru today. That single action does more than everything else on this list combined.