How Do You Stay Safe Around Lake Kawaguchi and Mount Fuji?

Published 2026-10-04 · Sources checked 2026-10-04 · Treasure Hunting Co., Ltd.

This guide is for visitors and longer-stay guests around Lake Kawaguchi. It covers Mount Fuji as an active volcano, the rules for climbing it, winter roads, safety on the lake, traffic in town and the numbers to call in an emergency.

We used pages from the Japan Meteorological Agency (JMA), Yamanashi Prefecture, Yamanashi Prefectural Police, Fujikawaguchiko Town, the national road office in Kofu, the Fire and Disaster Management Agency and the official Mt. Fuji climbing site. All were read on 2026-10-04. In a real emergency, follow local announcements and staff instructions first.

Mount Fuji is an active volcano

JMA watches Mount Fuji around the clock. It uses seismometers, tiltmeters, infrasound sensors, GNSS and cameras. On the day we checked, JMA's status was Volcanic Alert Level 1, which means "be aware this is an active volcano". It had no current warnings.

JMA's record shows why the watch matters. Lava flowed from the mountain's flanks between 864 and 866. In 1707, an eruption on the south-east flank dropped heavy ash as far as Edo, today's Tokyo. Many deep, low-frequency earthquakes were recorded in 2000 and 2001.

JMA issues warnings for residential areas at Levels 4 and 5. Levels 2 and 3 apply near the crater.

Hazard maps and evacuation maps

Yamanashi Prefecture publishes the Mount Fuji hazard map, revised in March 2021. It shows where lava flows, pyroclastic flows and mudflows from melting snow could reach. The prefecture says the hazard map is the basis for evacuation plans and simpler disaster maps.

Fujikawaguchiko Town points readers to the Mount Fuji volcano evacuation map made by the Mount Fuji Volcano Disaster Prevention Council. The council is made up of ten towns and cities at the north foot of the mountain, including Fujikawaguchiko. If you stay for a while, look up where your lodging sits on that map.

Climbing rules on the Yoshida Trail

The Yoshida Trail starts on the Yamanashi side. Under a prefectural ordinance, Yamanashi applies these rules from 1 July to 10 September:

• Time limit. The gate at the 5th station is closed from 14:00 to 3:00. Climbers staying in a mountain hut are exempt.
• Number limit. Up to 4,000 climbers a day. When the limit is reached, the gate closes.
• Fee. 4,000 yen per person per climb. You can pay on site or through the prefecture's trail booking system.

From fiscal 2026, people who walk only between Umagaeshi at the foot and the 5th station gate do not pay the fee. They must apply on the day at a set place.

Outside the climbing season

The official Mt. Fuji climbing site says the 2026 season has ended. All trails to the summit are now closed. Under the Road Act, the route from the 5th station to the summit is closed to use. Breaking this can bring up to six months in prison or a fine of up to 300,000 yen.

The site explains why climbing out of season is so dangerous:

• First-aid centers, toilets and mountain huts are closed and cannot be used as shelters.
• It is below freezing at the summit for most of the closed season. From November to April it is especially cold, below minus 10 °C.
• Average winds are said to be over 15 m/s, with gusts above 40 m/s.
• Trails are not repaired, and signs and ropes are taken away.
• Mobile phone coverage almost disappears once the extra base stations are removed.

The site's safety guidelines ban out-of-season climbing by anyone not fully prepared. Those who do go must submit a climbing plan and carry a portable toilet.

Winter roads

Snow can be heavy here. A Yamanashi road safety leaflet says 143 cm of snow fell at Kawaguchiko in February 2014.

The same leaflet says that on snowy or icy roads, drivers must fit chains or winter tires. Without them you may be fined up to 50,000 yen. It asks drivers to check road information before setting out and to fit chains early.

Ice can start early in the season. In 2023, the national road office in Kofu first spread anti-freezing agent on 13 November. That included Route 139 as far as Shoji in Fujikawaguchiko Town.

On the lake

Yamanashi's Fuji Five Lakes Water Safety Ordinance sets rules for boats on the five lakes. Yamanashi Prefectural Police explain it like this:

• No-go zones. Lake Kawaguchi has two zones marked by red buoys. Boats may not enter them.
• Safety zones. Lake Kawaguchi also has six zones marked by orange buoys. They protect swimmers and rowing boats. From 20 April to 15 September, powered boats may not enter.
• Weather. In fog or mist, boats must sound a horn. If the weather changes suddenly, they must move to a safe place.
• Alcohol. Operating a boat while drunk is banned.
• Accidents. After a boat accident, the people on board must rescue anyone hurt or in the water at once. They must also report the accident to the police quickly.

Traffic and fire in town

Fujikawaguchiko Town says traffic accidents happen often in the town. It asks people to cross only where they can see clearly in both directions. A car at 50 km/h covers 15 m every second. At night, reflective items make you visible from much further away.

The intersection by the Katsuyama branch office has the town's only pedestrian-scramble signal. All traffic lights turn red while all walk signals turn green. Walkers press a button to get a green signal.

Since 1 January 2026, forest fire advisories and warnings have been in use. While one is in force, outdoor bonfires and fireworks are not allowed. Smoking outdoors near flammable things is also not allowed.

Emergency numbers

• 110: police. Yamanashi Prefectural Police ask callers to say what happened, where and when. Give a landmark if you do not know the address. On a public phone, press the emergency button first, then dial 110.
• 110 app. If you cannot speak on the phone, the national 110 app lets you report by text. You must register before you use it.
• #9110: police advice. Use it for matters that are not urgent.
• 119: ambulance and fire. The Fire and Disaster Management Agency says to call 119 when you need an ambulance. Tell the operator first that it is a medical emergency. Anyone in Japan can use the service.
• #7119: medical advice. Fujikawaguchiko Town says this phone line started in October 2023. Doctors and nurses give advice when you are unsure whether you need an ambulance.

What we could not verify, and therefore left out

• Which parts of the lake shore lie in each hazard zone on the Mount Fuji maps. We did not read the map sheets themselves.
• The 2027 climbing season dates and fee. Yamanashi had not published them on the pages we read.
• Rules for swimming in Lake Kawaguchi. The police page covers boats, not swimmers.
• Where chain-only sections apply on roads near the lake this winter.
• Whether 110, 119, #9110 and #7119 calls are answered in English. The official pages we read did not say.

Related guides

• How Do You Get to Lake Kawaguchi from Tokyo?
• Why Is Lake Kawaguchi Part of the Mount Fuji World Heritage Site?

Sources

All URLs retrieved 2026-10-04.

1. 火山活動の状況（富士山） (Japan Meteorological Agency) — (Level 1 status; no current warnings)
2. 富士山 (Japan Meteorological Agency) — (monitoring instruments; 864 to 866 lava; 1707 eruption; 2000 to 2001 earthquakes)
3. Volcanic Warnings and Volcanic Alert Levels (Japan Meteorological Agency) — (Levels 4 and 5 for residential areas; 2 and 3 near the crater)
4. 富士山ハザードマップ（令和3年3月改定） (Yamanashi Prefecture) — (revised March 2021; hazards mapped; basis for plans)
5. 富士山火山防災避難マップ (Fujikawaguchiko Town) — (town points to the council's evacuation map)
6. 富士山火山防災協議会 (Fujiyoshida City) — (council of ten towns and cities including Fujikawaguchiko)
7. 山梨県富士山吉田口県有登下山道の通行について (Yamanashi Prefecture) — (season, gate hours, daily limit, 4,000 yen fee, payment, Umagaeshi exemption)
8. The Official Website for Mt. Fuji Climbing (Council for the Promotion of Appropriate Use of Mt. Fuji) — (2026 season ended; trails closed)
9. Mt. Fuji outside of the climbing season (Council for the Promotion of Appropriate Use of Mt. Fuji) — (Road Act closure and penalty; closed facilities; cold; wind; trails; phones; guidelines)
10. About the Council (Council for the Promotion of Appropriate Use of Mt. Fuji) — (secretariat: Ministry of the Environment, Yamanashi and Shizuoka)
11. 冬期の運転は事前の情報収集と早めのタイヤチェーン装着を (Yamanashi Prefecture) — (143 cm at Kawaguchiko in February 2014; chains or winter tires; fine)
12. 今冬初、甲府河川国道事務所管内で凍結防止剤を散布 (MLIT Kofu River and National Highway Office) — (first anti-freezing agent 13 November 2023 on Route 139)
13. 山梨県富士五湖水上安全条例について (Yamanashi Prefectural Police) — (no-go and safety zones on Lake Kawaguchi; weather; alcohol; accidents)
14. 交通事故発生マップ公開中 (Fujikawaguchiko Town) — (frequent accidents; crossing advice; 15 m per second; reflectors)
15. 【勝山地区】歩車分離式交差点に注意 (Fujikawaguchiko Town) — (pedestrian-scramble signal at Katsuyama)
16. 「林野火災注意報・林野火災警報」の運用開始について (Fujikawaguchiko Town) — (forest fire advisories from 1 January 2026; limits on fire use)
17. 110番のかけ方 (Yamanashi Prefectural Police) — (what to say; public phone button)
18. 110番アプリシステム (Yamanashi Prefectural Police) — (110 app for text reports; registration)
19. 緊急性のない事件・事故・相談事など (Yamanashi Prefectural Police) — (#9110 for non-urgent matters)
20. Guide for Ambulance Services (Fire and Disaster Management Agency) — (call 119; say medical emergency; anyone in Japan)
21. 急な病気やケガで迷った時は、#７１１９へ (Fujikawaguchiko Town) — (#7119 since October 2023)