Disasters · Volcano

What to do if a volcano erupts during your Japan trip

If you see an eruption near a volcano or receive an eruption bulletin, stop sightseeing and hiking and protect your head and body. Move to a nearby shelter or follow on-site guidance to get away from the crater. Eruption alert levels describe danger zones and required actions in five levels. Level 1 does not guarantee safety. An eruption can start suddenly before any warning is issued.

Official sources checked: 2026-10-12

If an eruption starts near the volcano

Don't stay to take photos or go closer to the crater. Cover your head with a helmet or backpack, and watch out for flying or falling rocks.
Move to a nearby volcanic shelter or mountain hut for evacuees. If there is none, protect yourself according to the situation around you, such as getting behind a nearby rock.
Follow the guidance of rangers, police, or firefighters to move away from the crater. If rocks are falling or the way down is dangerous, you may need to take cover nearby first. Whether to descend immediately or shelter first depends on the conditions on site.
If you need an ambulance or firefighters urgently, call 119. Give the volcano's name, nearby facilities, and the names on trail signs to explain where you are.

Official sources: Japan Meteorological Agency · What to do when you receive an eruption bulletin (in Japanese) ↗ · Japan Meteorological Agency · What to do if you encounter an eruption or falling volcanic ash on Mount Mihara (in Japanese) ↗ · JNTO · What to do if a volcano erupts in front of you (in Korean) ↗ · JNTO · Traveller support hotline and emergency contacts (in English) ↗
Sources checked: 2026-10-12

How to read Japanese signs and notices

If you see the Japanese terms below on signs or phone alerts, check what they mean. Don't just look at the numbers — read what kind of danger they describe and which areas or sections they apply to.

立入禁止

Meaning It means you must not enter this area.

What to do Don't go past signboards or barrier tape. If you are already inside a restricted zone, leave following on-site guidance.

Don't enter restricted areas even if the volcano alert level is low or other people go in. The photo above is a past example, so check on-site guidance for whether the area is currently restricted.

Official sources: Ministry of the Environment, Chubu Regional Office · Murododaira no-entry sign and control barrier example (in Japanese) ↗
Checked: 2026-10-12

火口周辺規制

Meaning It means entry is restricted around the volcanic crater.

What to do Read the restricted range in the notice and don't enter it.

This is wording used at volcano alert level 2. Restricted distances differ by volcano, so don't approach the crater based on the level number alone.

Official sources: Japan Meteorological Agency · Volcano disaster-prevention terms and precautions (in Japanese) ↗
Checked: 2026-10-12

入山規制

Meaning It means entry to or hiking in parts of the mountain is restricted.

What to do Don't start hiking in a restricted zone. If you are already inside one, leave following the on-site staff's guidance.

This is generally the wording for volcano alert level 3. Don't stay inside a restricted zone to take photos or look at observation decks.

Official sources: Japan Meteorological Agency · Volcano disaster-prevention terms and precautions (in Japanese) ↗
Checked: 2026-10-12

噴火速報

Meaning It is a notice that quickly reports the fact that a volcano has erupted.

What to do If you are near the volcano, stop sightseeing or hiking and protect your head and body. Depending on the situation and on-site guidance, enter a nearby shelter or move away from the crater.

It doesn't warn of an eruption in advance. If you see an eruption before any alert, don't wait for one.

Official sources: Japan Meteorological Agency · What an eruption bulletin means and what to do (in Japanese) ↗
Checked: 2026-10-12

退避壕

Meaning It is a volcanic shelter for temporarily protecting yourself from falling rocks and similar hazards.

What to do If one is nearby and accessible while rocks are falling from an eruption, enter it following on-site guidance to protect yourself temporarily.

It is different from a shelter where you stay overnight. It doesn't protect against every volcanic hazard, and you must check on site whether you can enter now.

Official sources: Japan Meteorological Agency · What tourists on Mount Mihara should do about eruptions, ejecta and volcanic ash (in Japanese) ↗
Checked: 2026-10-12

Red X-shaped barrier and no-entry sign blocking the Jigokudani direction in a snowy field — 「立入禁止」 means no entry. Even if you can't read all the Japanese, don't go past X-shaped barriers or cordons. This is an example of the sign toward Jigokudani at Murododaira on Mount Tateyama; the photo is from April 12, 2018, so it doesn't show whether the trail is open now or how much snow there is.
Source: Ministry of the Environment, Chubu Regional Office · 「室堂平の利用について」 · PDL1.0 · Used unchanged · Terms of use
Sources and terms of use checked: 2026-10-12

What should I check before visiting a volcano?

Check the warnings for the volcano you plan to visit, and find out whether you may enter the crater area and trails. Don't set out based on the alert level number alone — also check whether the local government or facilities have closed any areas.

The Ministry of the Environment's hiking guide for Mount Aso · 阿蘇山 says not to enter trails restricted because of earthquakes, heavy rain, or volcanic gas. When visiting other volcanoes, follow that place's entry restrictions too. Trails can be closed for other hazards even when there is no eruption warning.

Even if shelters are marked on a map, check separately whether you can use one now. Don't assume that having shelters means you can avoid every volcanic hazard.

Find the volcano you plan to visit on the Japan Meteorological Agency site and check when warnings were issued and which danger zones they cover. Some volcanoes don't use alert levels, so even without a number, read the danger range and action guidance in the warning.
Look for closed trails and observation decks in notices from the local government, national park, or facilities. On site, don't go past no-entry signs or barrier tape.
Find nearby shelters and the way down the mountain on a volcano guide map in advance. Saving the maps and your accommodation's address on your phone lets you view them even if the internet goes out.
When hiking, bring a helmet and the equipment recommended for that mountain. If entry is restricted or you can't prepare properly, it's better to drop the plans around the crater.

Official sources: Japan Meteorological Agency · Eruption warnings and activity information by volcano (in Japanese) ↗ · Japan Meteorological Agency · Hazard zones and evacuation maps by volcano (in Japanese) ↗ · Japan Meteorological Agency · What eruption warnings and forecasts mean (in Japanese) ↗ · Ministry of the Environment · Where not to go on Mount Aso and how to prepare for hiking (in Japanese) ↗ · Japan Meteorological Agency · What to do if you encounter an eruption or falling volcanic ash on Mount Mihara (in Japanese) ↗
Sources checked: 2026-10-12

Is it safe to go at eruption alert level 1?

No. At level 1 you still need to remember it's an active volcano. Volcanic ash and other ejecta can come out of the crater, and there's no guarantee the level rises in order.

The Japan Meteorological Agency announces danger zones and required actions in five eruption alert levels (噴火警戒レベル). Even at the same level, the closed-off range and evacuation methods differ by volcano. Don't apply another volcano's closure distances or evacuation guidance as-is.

Level 1 · Doesn't mean it's safe

Check the activity information for the volcano you plan to visit and follow on-site guidance. Depending on conditions, you may not be able to enter the crater.

Level 2 · Don't enter the crater area

Look at the danger zones in the warning and the barrier tape on site, and don't go into the restricted crater area.

Level 3 · Stop hiking where it's restricted

Don't enter areas with hiking bans or entry restrictions. You also must not keep sightseeing or viewing observation decks in restricted areas.

Level 4 · People who need help evacuating move first

In residential areas under evacuation orders, older people and others who need help evacuate first, and everyone else should prepare to evacuate. Travellers should also follow the local government's guidance where they are.

Level 5 · Leave the evacuation-target area

Leave the danger zone following the local government's guidance on evacuation places and how to move.

An eruption can start suddenly with no clear anomalies observed. If an eruption starts in front of you, don't wait for the level to rise or for a phone alert — protect your head and body.

Learn what the alert levels mean from the Japan Meteorological Agency (in Japanese) ↗

What if it erupts in front of me without any warning?

Don't wait for an alert — protect your head and body. Get away from falling rocks by taking cover in a nearby shelter or coming down the mountain. How to escape depends on the danger where you are and on-site guidance.

The Japan Meteorological Agency's eruption bulletin (噴火速報) quickly reports that a volcano has already erupted. It is not an advance warning of an eruption. It can also be issued for volcanoes with no prior warning once an eruption starts.

If you can come down, descend right away; if you need to take cover first from falling rocks, hide in a nearby shelter, hut, or behind rocks. If you haven't entered the mountain yet, stop and move away from it. Don't just run for a distant descent route while rocks are falling.

Large rocks flying from the volcano, or pyroclastic flows — hot ash and gas rushing down fast — may leave you almost no time to evacuate once they happen. Even with a helmet and shelters, don't enter restricted zones.

Don't go back into a restricted zone to restart sightseeing or get your luggage just because the smoke from the crater has lessened. Follow the local government or facility's guidance on whether it's okay to return.

Official sources: Japan Meteorological Agency · What to do when you receive an eruption bulletin (in Japanese) ↗ · Japan Meteorological Agency · What to do if you encounter an eruption or falling volcanic ash on Mount Mihara (in Japanese) ↗ · Japan Meteorological Agency · What eruption warnings and forecasts mean (in Japanese) ↗ · JNTO · What to do if a volcano erupts in front of you (in Korean) ↗ · JNTO · What to do when an eruption warning is issued (in Korean) ↗
Sources checked: 2026-10-12

Semicircular concrete volcanic shelter with its entrance open, beside a tree — 「退避壕」 is a volcanic shelter for temporarily protecting yourself from falling rocks and similar hazards. It is different from an overnight shelter. This is an example from the Japan Meteorological Agency's guide for tourists on Mount Mihara; it doesn't mean other volcanoes have the same facilities or that you can enter one now.
Source: Japan Meteorological Agency · 「三原山に登る観光客のみなさまへ」 · PDL1.0 · Used unchanged · Terms of use
Sources and terms of use checked: 2026-10-12

What if volcanic ash falls on the city or my accommodation?

Close windows so ash doesn't get indoors. If you have to be outside, protect yourself with a dust mask against ash and dust goggles for your eyes. If you've been told to evacuate, don't keep staying indoors — move as instructed.

Breathing in volcanic ash can cause coughing or breathing difficulty. If it gets in your eyes, they can itch, hurt, and turn red — don't rub them. Even with a mask and goggles, don't enter a restricted crater or anywhere with volcanic gas.

The Japan Meteorological Agency's volcanic ash forecast (降灰予報) tells you where and how much ash will fall. Check the time it was issued, whether your area is included, and how much is expected. Wind can make the actual areas and amounts differ from the forecast.

If the forecast says 「多量」, it means a large amount of ash is expected. Avoid going out and driving then. If blowing ash reduces visibility, it's better to stop sightseeing or driving a rental car. Wet ash on roads can be slippery.

Official sources: JNTO · How to protect your airways and eyes from volcanic ash (in Korean) ↗ · Japan Meteorological Agency · What the volcanic ash forecast means (in Japanese) ↗ · Japan Meteorological Agency · What to do based on how much volcanic ash falls (in Japanese) ↗ · Japan Meteorological Agency · What to do if you encounter an eruption or falling volcanic ash on Mount Mihara (in Japanese) ↗ · Tokyo Metropolitan Government · How to protect yourself when ash falls and road precautions (in Japanese) ↗
Sources checked: 2026-10-12

Can I keep travelling after the eruption?

If you've been told to evacuate, stop sightseeing and evacuate first. Then check whether you can stay at your accommodation and whether transport to your next destination is running. One volcano's alert level alone can't tell you whether to cancel your whole Japan trip or keep going.

Where ash has piled up, rain can bring mudflows — soil and rocks washing down all at once — so watch out for those too. Don't just check eruption warnings; also look at heavy-rain information and new evacuation notices from the local government.

Before setting out, check the latest notices from your accommodation and transport operators. Having a booking doesn't mean you can enter your accommodation now or that trains and buses are running.

Check the local government's guidance for whether your location and accommodation are under evacuation orders. If your accommodation is in an evacuation zone or the way there is closed, don't set out to go back.
From somewhere safe, call your accommodation to ask whether you can stay tonight and whether the way there is restricted. If you can't stay, find somewhere to stay following the area's evacuation guidance.
Check on the airline's website or app whether your booked flight will operate. Separately check whether the trains and buses to the airport are running and whether roads are blocked. Even if your flight is scheduled to operate, you may not be able to reach the airport.
If it's unclear whether you can stay at your accommodation or reach your next destination, it's better to cut the plans around the volcano first. If you need to change or cancel bookings, ask the company you booked with about the conditions. A disaster doesn't mean every booking can be cancelled for free.

Official sources: Japan Meteorological Agency · Terms used in volcano warnings and precautions (in Japanese) ↗ · JNTO · What to do when an eruption warning is issued (in Korean) ↗ · JNTO · Official sites for disaster and transport information (in English) ↗
Sources checked: 2026-10-12

Who should I call if I'm hurt or need help?

If you urgently need an ambulance or firefighters, call 119. Once you have evacuated somewhere safe, you can contact the JNTO traveller support hotline if you need help during your trip.

When your call connects, give the volcano's name, nearby facilities, and the names on trail signs. If someone is injured, describe their condition too. If it's hard to explain your location or you can't communicate, ask nearby staff to help with the call.

The JNTO traveller support hotline is 050-3816-2787. It's available 24 hours a day, every day, in Korean, English and Chinese. From overseas, call +81-50-3816-2787. If you need an emergency ambulance, contact 119 before the JNTO hotline.

If you can't stay at your accommodation, tell the shelter staff so. If you need water or medicine, or want to ask for interpretation, say what you need. But supplies and interpretation aren't guaranteed right away.

Official sources: JNTO · Traveller support hotline and emergency contacts (in English) ↗
Sources checked: 2026-10-12

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Frequently asked questions

Do eruption alert levels rise in order from 1 to 5?

Not necessarily in order. An eruption can happen with no clear anomalies observed. Even at level 1, don't enter restricted areas. If you see an eruption, protect your head and body without waiting for an alert.

Official sources: Japan Meteorological Agency · Terms used in volcano warnings and precautions (in Japanese) ↗ · Japan Meteorological Agency · What to do when you receive an eruption bulletin (in Japanese) ↗
Sources checked: 2026-10-12

If I get an eruption bulletin, must I descend immediately?

It depends on the situation. If you can descend, do it right away; if rocks are falling and you need to take cover first, hide in a nearby shelter, hut, or behind rocks. Don't just run for a distant descent route — move away from the crater following on-site guidance.

Official sources: Japan Meteorological Agency · What to do when you receive an eruption bulletin (in Japanese) ↗ · Japan Meteorological Agency · What to do if you encounter an eruption or falling volcanic ash on Mount Mihara (in Japanese) ↗ · JNTO · What to do if a volcano erupts in front of you (in Korean) ↗
Sources checked: 2026-10-12

Should I close windows even when only a little ash is falling?

Yes. The Japan Meteorological Agency advises closing windows even when only a little ash falls. Outside, protect yourself with a dust mask and dust goggles, and don't rub your eyes if ash gets in them. If you've been told to evacuate, evacuating takes priority over closing windows and staying inside.

Official sources: Japan Meteorological Agency · What to do based on how much volcanic ash falls (in Japanese) ↗ · JNTO · How to protect your airways and eyes from volcanic ash (in Korean) ↗ · Japan Meteorological Agency · What to do if you encounter an eruption or falling volcanic ash on Mount Mihara (in Japanese) ↗ · JNTO · What to do when an eruption warning is issued (in Korean) ↗
Sources checked: 2026-10-12

Can I go back to a restricted observation deck once the eruption calms down?

Don't enter a restricted zone just because the smoke from the crater has lessened. Check whether the local government or facility says it's okay to return. Even at the same level, the closed-off range differs by volcano, so don't apply another mountain's guidance as-is.

Official sources: Japan Meteorological Agency · Terms used in volcano warnings and precautions (in Japanese) ↗ · Japan Meteorological Agency · What eruption warnings and forecasts mean (in Japanese) ↗ · Ministry of the Environment · Where not to go on Mount Aso and how to prepare for hiking (in Japanese) ↗
Sources checked: 2026-10-12

When an eruption warning is lifted, are the other dangers over too?

No. Where ash has piled up, rain can bring mudflows of soil and rocks — dangers an eruption warning alone can't tell you about. Check heavy-rain information and local evacuation notices together, and don't enter areas blocked off on site.

Official sources: Japan Meteorological Agency · Terms used in volcano warnings and precautions (in Japanese) ↗ · JNTO · What to do when an eruption warning is issued (in Korean) ↗
Sources checked: 2026-10-12

Can I ask for help in English in Japan?

You can contact the JNTO traveller support hotline at 050-3816-2787, 24 hours a day, every day, in Korean, English and Chinese. If you urgently need an ambulance or firefighters, call 119 first. Contacting the JNTO hotline doesn't guarantee immediate rescue or supplies and interpretation at shelters.

Official sources: JNTO · Traveller support hotline and emergency contacts (in English) ↗
Sources checked: 2026-10-12

Official sources for this guide

Check the area's notices for current warnings and access restrictions. Check the transport operators' latest notices to see whether trains and flights are running.