How Do You Stay Safe from Tsunamis on Shimoda's Beaches? Warnings, Maps and Emergency Numbers
This guide is for visitors spending time on Shimoda's beaches and harbour front. It explains what to do if you feel an earthquake near the sea, how Japan's tsunami warnings work, where to find Shimoda's evacuation maps, and which numbers to call in an emergency.
We used pages from Shimoda City, the Japan Meteorological Agency (JMA), the Japan Tourism Agency's safety site, the Japan Coast Guard, the Fire and Disaster Management Agency and Shizuoka Prefectural Police. All were read on 2026-10-03. Rules and maps can change. In a real emergency, follow local announcements and staff instructions first.
Why Shimoda takes tsunamis seriously
Shimoda City's tsunami hazard map gives the town's record. Since the 18th century, three tsunamis caused heavy damage to the town and port. They followed the Genroku Kanto earthquake of 1703, the Hoei Tokai earthquake of 1707 and the Ansei Tokai earthquake of 1854.
The map adds that tsunamis have reached Shimoda five times in less than 100 years, without major damage. It warns that tsunamis from far away, such as from earthquakes off Chile, also need care.
Shizuoka Prefecture's fourth earthquake damage estimate expects shaking of upper 5 to lower 6 on the Japanese intensity scale in Shimoda if a Nankai Trough megaquake happens. The city stresses that this is only an estimate, and shaking could be stronger.
If the ground shakes while you are near the sea
The city's hazard map says to start evacuating at once if any of these happen:
- You feel a strong earthquake, around intensity 4 or more.
- You feel slow shaking that goes on for a long time.
- A tsunami warning or advisory is issued, or you hear a call to evacuate.
- The sea does something unusual, such as suddenly pulling back.
Its advice on how to evacuate:
- Go as high and as far as you can, and do not trust the estimates.
- Go on foot where possible. Cars can be stopped by damaged roads, fallen buildings and traffic jams, and they block people on foot.
- Do not wait for the sea to pull back. A tsunami can arrive without it.
- Stay away from rivers too. A tsunami can travel several kilometres up a river.
- A tsunami only 20 to 30 cm high can sweep a person away.
- If the earthquake is close to the coast, a warning may not come in time. The rule is "shaking means evacuate".
The Japan Tourism Agency's safety site gives the same message for waterfronts. Watch what the people around you do, and go to high ground or a tsunami shelter.
How JMA tsunami warnings work
JMA issues tsunami warnings and advisories by region, based on the estimated tsunami height. It aims to issue them about three minutes after an earthquake. There are three levels:
- Tsunami Advisory: up to 1 metre. Get out of the water and leave the coast at once.
- Tsunami Warning: up to 3 metres. Evacuate from coasts and riversides to high ground or a tsunami evacuation building.
- Major Tsunami Warning: more than 3 metres. Heights are given as 5 m, 10 m or over 10 m. Evacuate at once.
For very large earthquakes, the first warning may use words instead of numbers. "Huge" is used for a Major Tsunami Warning, and "High" for a Tsunami Warning. If "Huge" is used, JMA says waves as large as those of the 2011 Great East Japan Earthquake may hit.
Waves come again and again, and later waves may be higher. Do not leave your evacuation place until the warning is cleared. Since 30 August 2013, Major Tsunami Warnings have been part of Japan's Emergency Warning system.
Tsunami flags and other alerts
Since summer 2020, JMA says flags have been used on the coast to show tsunami warnings. The flag has a red and white checked pattern. It helps people who cannot hear well and swimmers who may not hear sirens over the wind and waves. If you see one, evacuate at once.
Shimoda City lists other ways alerts reach people. They include TV, radio, the internet and the city's disaster radio system. Emergency alert messages also go to mobile phones that can receive them within the city. The city also runs an email service with earthquake, tsunami and weather news.
Shimoda's maps, evacuation sites and height above sea level
Shimoda City publishes tsunami hazard maps and tsunami evacuation plan maps as PDFs on its website. They cover the Shimoda, Shirahama, Hamasaki, Inozawa and Asahi districts. Printed copies are handed out at the Disaster Safety Division counter in the city office.
The evacuation plan maps mark designated emergency evacuation sites, temporary evacuation sites, tsunami evacuation buildings and recommended directions to run. They also show when flooding is expected to begin in each area. For the central Shimoda district, the list of designated emergency evacuation sites includes Shimoda Park and Chorakuji temple.
The city also has an online "height above sea level" map. Click any point to see its height. It suggests checking the height of the places where you spend time, and of nearby evacuation sites, before anything happens.
The Japan Tourism Agency notes that some hotels and inns are designated to take in evacuees during a disaster. Ask your accommodation.
Beaches: the season and lifeguards
Shimoda City lists nine official swimming beaches. In 2026 they opened on 18 July and closed between 23 and 31 August, depending on the beach. Most opened from 8:00 to 16:00.
The city warns that outside the season and outside these hours, there are no lifeguards or other watchers on the beaches. It also says that other shores in Shimoda are not swimming beaches.
Six of the nine have been certified by the Japan Lifesaving Association after a review of beach safety: Shirahama Chuo, Shirahama Ohama, Sotoura, Tatadohama, Iritahama and Kisami Ohama.
Emergency numbers: 110, 119 and 118
- 110: police. Shizuoka Prefectural Police say 110 is the emergency line for incidents and accidents. Be ready to say what happened, the current situation, where and when.
- 119: ambulance. The Fire and Disaster Management Agency's guide says to call 119 when you need an ambulance. Anyone in Japan can use the service. If people nearby speak Japanese, ask them to help you call.
- 118: Japan Coast Guard. 118 is the Coast Guard's emergency number for incidents and accidents at sea. Use it if you are in or see a sea accident, or spot an oil spill or a suspicious boat. Calmly say when, where and what happened.
The Coast Guard also runs NET118, a text-based service for people with hearing or speech difficulties. Users must register in advance.
What we could not verify, and therefore left out
- Whether 110, 119 and 118 calls are answered in English. The official pages we read did not say.
- Whether Shimoda's email alert service and maps come in English.
- When flooding would begin at each beach. The city's maps show this by area, but we did not read them beach by beach.
- Where tsunami flags are flown in Shimoda, and whether they are used outside the swimming season.
- Rip currents and other beach hazards. We found no official Shimoda page on them.
Related guides
- How do you get to Shimoda from Tokyo? Trains via Atami and Ito, and buses from the station
- What is Shimoda's Black Ships history? Perry, the Shimoda Treaty and the temples where it happened
Sources
All URLs retrieved 2026-10-03.
- 下田市津波ハザードマップ・津波避難計画地図のご案内 (Shimoda City) — (maps for five districts; where to get printed copies)
- 下田市津波ハザードマップ 記事面 下田地区 (Shimoda City) — (past tsunamis; estimated shaking; when and how to evacuate; alert channels; email service)
- 下田市津波避難計画地図 下田地区 (Shimoda City) — (map legend; evacuation sites in central Shimoda)
- ひと目で分かる！「ここは海抜何メートル」 (Shimoda City) — (online height above sea level map)
- 海水浴場 (Shimoda City) — (nine swimming beaches; 2026 season and hours; no lifeguards outside them; JLA certification)
- Tsunami Warning/Advisory and Tsunami Information (Japan Meteorological Agency) — (warning levels, heights, actions, timing, "Huge" and "High", Emergency Warnings)
- Tsunami flags (Japan Meteorological Agency) — (red and white flags since summer 2020)
- Waterfronts (coastal areas, riversides) (Japan Tourism Agency, Safety tips for travelers) — (what to do on the waterfront after an earthquake)
- Safety tips for travelers (Japan Tourism Agency) — (warning about three minutes after a quake; hotels as shelters)
- 「110番」を適切に利用するには？ (Shizuoka Prefectural Police) — (what 110 is for; what to tell the operator)
- Guide for Ambulance Services (Fire and Disaster Management Agency) — (call 119 for an ambulance; anyone in Japan can use it)
- 海の「事件・事故」は118番 (Japan Coast Guard) — (118 for incidents and accidents at sea; NET118)