If a volcano erupts during your Japan trip
If you witness an eruption near a volcano or receive an eruption bulletin, stop sightseeing and hiking and protect your head and body. Take shelter in a nearby evacuation facility or move away from the crater as directed on site. Eruption alert levels show the danger zone and required actions in five steps. Level 1 doesn't guarantee safety. An eruption can also start suddenly before any warning.
Official sources checked: 2026-10-12
If an eruption starts near you
- Don't linger 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.
- Take shelter in a nearby volcanic evacuation facility or mountain hut. If there isn't one, protect yourself according to the situation around you, for example behind a nearby rock.
- Move away from the crater as directed by wardens, police or fire services. If rocks are falling or the way down is dangerous, you may need to take cover nearby first. Whether to descend the mountain right away or shelter first depends on the situation on site.
- Call 119 if you need an ambulance or urgent fire-service help. Give the volcano's name, nearby facilities and the names on trail signs so they know where you are.
Official sources: Japan Meteorological Agency: what to do when you receive an eruption bulletin ↗ · Japan Meteorological Agency: what to do about eruptions and volcanic ash on Mount Mihara ↗ · JNTO: what to do if a volcano erupts in front of you (in Korean) ↗ · JNTO: traveller support hotline and ambulance/fire contacts ↗
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How to read Japanese signs and notices
If you see the Japanese below on a sign or a phone alert, check what it means. Don't just look at the numbers — read what danger it warns about and which area or section it applies to.
立入禁止
Meaning It means you must not enter that zone.
What to do Don't go past signboards or barrier tape. If you're already inside a restricted zone, leave it as directed on site.
Don't enter restricted areas even if the volcanic alert level is low or other people are going in. The photo above is an old example, so check on-site guidance for what's currently closed.
Official sources: Ministry of the Environment, Chubu Regional Environment Office: Murododaira no-entry sign and control bar example ↗
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火口周辺規制
Meaning It means entry around the volcanic crater is restricted.
What to do Read the restricted area in the notice and don't go inside it.
This is the wording used at volcanic 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: volcanic disaster-prevention terms and cautions ↗
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入山規制
Meaning It means entry to part of the mountain or hiking there is restricted.
What to do Don't start hiking in a restricted zone. If you're already inside one, leave as directed by on-site staff.
This is generally the wording for volcanic alert level 3. Don't linger in a restricted zone to take photos or look at viewpoints.
Official sources: Japan Meteorological Agency: volcanic disaster-prevention terms and cautions ↗
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噴火速報
Meaning It's a notice that quickly tells you a volcano has erupted.
What to do If you're near the volcano, stop sightseeing or hiking and protect your head and body. Depending on the situation and on-site guidance, enter a nearby evacuation facility or move away from the crater.
It's not advance warning of an eruption. If you witness an eruption before the alert, don't wait for it.
Official sources: Japan Meteorological Agency: what an eruption bulletin means and what to do ↗
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退避壕
Meaning It's a volcanic evacuation facility for temporarily protecting yourself from falling rocks.
What to do If rocks are falling from an eruption and one is close and reachable, enter it as directed on site to temporarily protect yourself.
It's different from a shelter where you stay or live. It doesn't protect against every volcanic danger, and you must check on site whether you can enter it now.
Official sources: Japan Meteorological Agency: what Mount Mihara tourists should do about eruptions, ejecta and ash ↗
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「立入禁止」 means no entry. Even if you can't read all the Japanese, don't go past the X-shaped control bars or barrier tape. This is an example sign from the Jigokudani direction at Murododaira on Mount Tateyama; the photo is from 12 April 2018, so it doesn't show whether the path is open now or how much snow there is.
Source: Ministry of the Environment, Chubu Regional Environment Office 「室堂平の利用について」 (About using Murododaira) · PDL1.0 · used as-is · Terms of use
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Official sources: Japan Meteorological Agency: what to do when you receive an eruption bulletin ↗ · Japan Meteorological Agency: what to do about eruptions and volcanic ash on Mount Mihara ↗ · JNTO: what to do if a volcano erupts in front of you (in Korean) ↗ · JNTO: traveller support hotline and ambulance/fire contacts ↗
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What should I check before visiting a volcano?
Check the warnings for the volcano you're visiting, and whether you may enter the crater 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.
Mount Aso (阿蘇山)'s Ministry of the Environment hiking guidance warns against entering trails closed 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 dangers even with no eruption warning.
Even if shelters are marked on the map, check separately whether you can use them now. Don't assume a shelter protects you from every volcanic danger.
- Find the volcano you're visiting on the Meteorological Agency site and check the warning's issue time and danger zone. Some volcanoes don't use alert levels, so even without a number, read the danger zone and action guidance in the warning.
- Find closed trails and viewpoints in notices from the local government, national parks or facilities. On site, don't go past no-entry signs or barrier tape.
- On a volcano guide map, find nearby evacuation shelters and the routes down the mountain in advance. Saving the maps and your accommodation address on your phone means you can still view them without internet.
- When hiking, bring the gear recommended for that mountain, such as a helmet. If entry is restricted or the preparations are hard to make, it's better to drop plans around the crater.
- Find warnings and activity information for your volcano (in Japanese) ↗
- View danger zones and evacuation guidance maps by volcano (in Japanese) ↗
- Cash and emergency supplies to pack before travelling in Japan →
Official sources: Japan Meteorological Agency: warnings and activity information by volcano ↗ · Japan Meteorological Agency: danger zones and evacuation guidance maps by volcano ↗ · Japan Meteorological Agency: what eruption warnings and forecasts mean ↗ · Ministry of the Environment: where not to go on Mount Aso and hiking preparation ↗ · Japan Meteorological Agency: what to do about eruptions and volcanic ash on Mount Mihara ↗
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Is it safe to go at eruption alert level 1?
No. Even at level 1, remember it's an active volcano. Ash and more can be ejected inside the crater, and there's no guarantee levels rise 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, restricted areas and evacuation methods differ by volcano. Don't apply another volcano's restricted distances or evacuation guidance as-is.
Level 1 · doesn't mean it's safe
Check the activity information for the volcano you're visiting and follow on-site guidance. You may not be able to enter the crater depending on conditions.
Level 2 · don't enter the crater area
Look at the danger zone in the warning and the barrier tape on site, and don't go near the restricted crater area.
Level 3 · stop hiking in restricted areas
Don't enter zones with hiking bans or entry restrictions. You mustn't keep sightseeing at viewpoints in restricted areas either.
Level 4 · people who need help evacuating move first
In residential areas subject to evacuation, elderly people and others who need help evacuate first, and everyone else should prepare to evacuate. Travellers should also follow the local government guidance where they are.
Level 5 · leave the evacuation zone
Leave the danger zone following the evacuation places and travel methods the local government directs.
An eruption can start suddenly with no clear abnormality observed. If an eruption starts in front of you, don't wait for the level to rise or a phone alert — protect your head and body.
Official sources: Japan Meteorological Agency: what the eruption alert levels mean ↗ · Japan Meteorological Agency: wording used in volcano warnings and cautions ↗ · Japan Meteorological Agency: what to do at each alert level ↗
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What if it erupts in front of me and I never got a warning?
Don't wait for an alert — protect your head and body. Get out of the way of falling rocks by taking cover in a nearby evacuation shelter or coming down the mountain. How you shelter depends on the danger where you are and on-site guidance.
The Meteorological Agency's eruption bulletin (噴火速報) quickly reports that a volcano has already erupted. It's not advance warning. It can be issued even for a volcano with no warning when an eruption starts.
If you can come down, descend right away; if you need to take cover first, shelter in a nearby evacuation facility or hut, or behind a rock. If you haven't entered the mountain yet, stop and stay 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 of hot ash and gas rushing down fast, can leave almost no time to evacuate once they start. Even with a helmet and shelters, don't enter restricted zones.
Don't restart sightseeing or go back into a restricted zone for your bags just because the smoke from the crater has lessened. Follow the local government or facility guidance on whether you may return.
Official sources: Japan Meteorological Agency: what to do when you receive an eruption bulletin ↗ · Japan Meteorological Agency: what to do about eruptions and volcanic ash on Mount Mihara ↗ · Japan Meteorological Agency: what eruption warnings and forecasts mean ↗ · 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) ↗
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「退避壕」 is a volcanic evacuation facility for temporarily protecting yourself from falling rocks. It's different from an overnight shelter. It's an example from the Meteorological Agency's Mount Mihara guidance, and doesn't mean other volcanoes have the same facilities or that you can enter them now.
Source: Japan Meteorological Agency 「三原山に登る観光客のみなさまへ」 (To tourists climbing Mount Mihara) · PDL1.0 · used as-is · Terms of use
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What if volcanic ash falls on the town or my accommodation?
Close windows so ash can't get indoors. If you must be outside, protect yourself with an ash-blocking dust mask and dust goggles for your eyes. If you're told to evacuate, don't stay indoors — follow those instructions.
Breathing in volcanic ash can cause coughing or difficulty breathing. If it gets in your eyes it can itch, hurt or redden them, so don't rub them. Even with a mask and goggles, don't enter a restricted crater or anywhere with volcanic gas.
The Meteorological Agency's ashfall forecast (降灰予報) tells you where and how much ash will fall. Check the issue time to see whether your area is included and how much is expected. Wind can make the actual places 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 hire car. Ash on roads can be slippery when wet.
- What the ashfall forecast means and what to do when ash falls (in Japanese) ↗
- How to protect yourself from volcanic ash, from JNTO (in Korean) ↗
Official sources: JNTO: how to protect your airways and eyes from volcanic ash (in Korean) ↗ · Japan Meteorological Agency: what the ashfall forecast means ↗ · Japan Meteorological Agency: what to do by ashfall amount ↗ · Japan Meteorological Agency: what to do about eruptions and volcanic ash on Mount Mihara ↗ · Tokyo Metropolitan Government: protecting yourself when ash falls and road cautions ↗
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Can I keep travelling after an eruption?
If you're 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 operating. You can't decide to cancel or continue your whole Japan trip based on one volcano's alert level alone.
If rain falls where ash has piled up, watch out for debris flows (lahars) of mud and rock rushing down at once. Don't just watch eruption warnings — also check heavy rain information and new evacuation guidance from the local government.
Before setting out, recheck the latest guidance from your accommodation and transport. Having a booking doesn't mean you can get into your accommodation now or that trains and buses are operating.
- Check the local government guidance for whether your location and accommodation are subject to evacuation. 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 closed. If you can't stay, find somewhere to stay following that area's evacuation guidance.
- Check whether your booked flight is operating on the airline's website or app. You also need to check separately whether trains and buses to the airport are operating and whether roads are closed. Even if your flight is scheduled, you may not be able to get to the airport.
- If you're unsure whether you can stay at your accommodation or reach your next destination, it's better to cut your volcano-area plans 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 is cancelled free of charge.
- Find evacuation notices for your area and shelters that are open →
- What to do when your flight is delayed or cancelled →
- Getting around Japan on public transport →
- Find official disaster and transport sites with JNTO (in English) ↗
Official sources: Japan Meteorological Agency: wording used in volcano warnings and cautions ↗ · JNTO: what to do when an eruption warning is issued (in Korean) ↗ · JNTO: official sites for disaster and transport information ↗
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Who do I call if I'm hurt or need help?
Call 119 if you need an ambulance or urgent fire-service help. Once you've evacuated somewhere safe, you can contact the JNTO traveller support hotline for help with travel difficulties.
When the call connects, give the volcano's name, nearby facilities and the names on trail signs. If someone is hurt, describe their condition too. If it's hard to explain your location or the language isn't working, ask nearby staff to help with the call.
The JNTO traveller support hotline is 050-3816-2787. It's available 24 hours a day in Korean, English and Chinese. From overseas, call +81-50-3816-2787. If you need an urgent ambulance, call 119 before JNTO.
If you can't stay at your accommodation, tell the shelter staff so. If you need water or medication, or want interpreting, just say what you need. But supplies or interpreting can't be guaranteed on the spot.
Official sources: JNTO: traveller support hotline and ambulance/fire contacts ↗
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Related guides
Frequently asked questions
Do eruption alert levels rise from 1 to 5 in order?
Not necessarily in order. An eruption can start with no clear abnormality observed. Don't enter restricted areas even at level 1. If you witness an eruption, don't wait for an alert — protect your head and body.
Official sources: Japan Meteorological Agency: wording used in volcano warnings and cautions ↗ · Japan Meteorological Agency: what to do when you receive an eruption bulletin ↗
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If I get an eruption bulletin, must I descend right away?
It depends on the situation. If you can come down, descend right away; if rocks are falling and you need to take cover first, shelter in a nearby evacuation facility or hut, or behind a rock. Don't just run for a distant descent route — move away from the crater as directed on site.
Official sources: Japan Meteorological Agency: what to do when you receive an eruption bulletin ↗ · Japan Meteorological Agency: what to do about eruptions and volcanic ash on Mount Mihara ↗ · JNTO: what to do if a volcano erupts in front of you (in Korean) ↗
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Should I close windows even when only a little ash is falling?
Yes. The Meteorological Agency advises closing windows even when only a little ash is falling. Protect yourself outside with a dust mask and dust goggles, and don't rub your eyes if ash gets in. If you're told to evacuate, evacuating takes priority over closing windows and staying put.
Official sources: Japan Meteorological Agency: what to do by ashfall amount ↗ · JNTO: how to protect your airways and eyes from volcanic ash (in Korean) ↗ · Japan Meteorological Agency: what to do about eruptions and volcanic ash on Mount Mihara ↗ · JNTO: what to do when an eruption warning is issued (in Korean) ↗
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Can I go back to a restricted viewpoint 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 you may return. Even at the same level, restricted areas differ by volcano, so don't apply another mountain's guidance as-is.
Official sources: Japan Meteorological Agency: wording used in volcano warnings and cautions ↗ · Japan Meteorological Agency: what eruption warnings and forecasts mean ↗ · Ministry of the Environment: where not to go on Mount Aso and hiking preparation ↗
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When the eruption warning is lifted, are other dangers over too?
No. If rain falls where ash has piled up, there are dangers an eruption warning alone can't tell you about, like debris flows (lahars) of mud and rock. Check heavy rain information and local evacuation guidance together, and don't enter places blocked off on site.
Official sources: Japan Meteorological Agency: wording used in volcano warnings and cautions ↗ · JNTO: what to do when an eruption warning is issued (in Korean) ↗
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Can I ask for help while travelling in Japan?
The JNTO traveller support hotline 050-3816-2787 is available 24 hours a day in Korean, English and Chinese. If you need an ambulance or urgent fire-service help, call 119 first. Contacting JNTO doesn't mean rescue or shelter supplies and interpreting are provided right away.
Official sources: JNTO: traveller support hotline and ambulance/fire contacts ↗
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Official sources for this guide
Check current warnings and entry restrictions in your area's notices. For whether trains and flights are operating, see the transport operators' latest notices.
Official sources: Japan Meteorological Agency: what the eruption alert levels mean ↗ · Japan Meteorological Agency: wording used in volcano warnings and cautions ↗ · Japan Meteorological Agency: what to do at each alert level ↗ · Japan Meteorological Agency: what eruption warnings and forecasts mean ↗ · Japan Meteorological Agency: what to do when you receive an eruption bulletin ↗ · Japan Meteorological Agency: what to do about eruptions and volcanic ash on Mount Mihara ↗ · Japan Meteorological Agency: warnings and activity information by volcano ↗ · Japan Meteorological Agency: danger zones and evacuation guidance maps by volcano ↗ · Japan Meteorological Agency: what the ashfall forecast means ↗ · Japan Meteorological Agency: what to do by ashfall amount ↗ · JNTO: what to do when an eruption warning is issued (in Korean) ↗ · JNTO: what to do if a volcano erupts in front of you (in Korean) ↗ · JNTO: how to protect your airways and eyes from volcanic ash (in Korean) ↗ · Ministry of the Environment: where not to go on Mount Aso and hiking preparation ↗ · Tokyo Metropolitan Government: protecting yourself when ash falls and road cautions ↗ · JNTO: traveller support hotline and ambulance/fire contacts ↗ · JNTO: official sites for disaster and transport information ↗
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