利尻山は快晴に恵まれ、視程は20km以上と良好だ。しかし山頂現況は気温3.1℃、体感は氷点下0.5℃と低く、山麓の12.5℃とは約9℃の大きな気温差がある。日中を通して山頂付近の気温は3〜4℃前後で推移し、風速は2.78〜4.33m/s、突風は10m/sを超える時間帯もあるだろう。防寒対策は必須となる。
積雪は0cmで、地面は基本的にドライコンディションだ。しかし日陰や北斜面、風の当たらない沢筋では湿り気や霜が残る可能性もある。特に9合目から山頂にかけての脆い火山礫地帯は、濡れていると滑りやすいため、足元には十分な注意が必要だ。アイゼンやチェーンスパイクは不要だが、防水防風のアウターレイヤー、フリースなどのミッドレイヤー、速乾性のベースレイヤーは必ず着用し、手袋と帽子も携行すること。
低体温症のリスクは日中の低温と風により常にある。行動中は体温が維持されても、休憩時や行動が停滞すると体温が奪われやすい。こまめな休憩と行動食でエネルギーを補給し、体温管理を徹底すること。雷のリスクは低いが、突風によるバランスの喪失には注意が必要だ。鴛泊コース、沓形コースともに、山頂直下は急峻な火山礫の斜面となるため、慎重な歩行を心がけること。
夕方18時以降は薄曇りとなり、気温は氷点下へと下がる。夜間は風もやや強まるため、日没後の行動は避けるべきだ。自動リスク判定では顕著な警戒値は検出されていないが、独立峰特有の海風による急なコンディション変化には常に意識を向け、無理な行動は控えること。
北海道
利尻山
Mt. Rishiri
2026年6月4日 08:05 更新
利尻は快晴広がるも山頂は低温 稜線風に備えよ
Clear Skies and Gentle Winds on Rishiri. Prepare for Cold Alpine Conditions.
現在の気象状況 — Current Conditions
▲ 山頂エリア (Summit)
気温 Temp
+3.1°C
風速 Wind
3.3m/s
ENE
天候 Weather
🌤️ ほぼ晴れ
体感 Feels Like
-0.5°C
▼ 登山口・山麓エリア (Base)
気温 Temp
+12.5°C
風速 Wind
3.3m/s
ENE
天候 Weather
🌤️ ほぼ晴れ
標高 Altitude
217m
山頂の3時間予報 — Summit Forecast
09:00
+4°C
2.8m/s
ENE
💧 0mm
(0%)
12:00
+3°C
4.2m/s
NE
💧 0mm
(0%)
15:00
+3°C
4.3m/s
NE
💧 0mm
(0%)
18:00
+1°C
4.1m/s
ENE
💧 0mm
(0%)
21:00
-1°C
4m/s
ENE
💧 0mm
(0%)
00:00
-1°C
4.4m/s
E
💧 0mm
(0%)
03:00
-1°C
4.2m/s
E
💧 0mm
(0%)
気象分析 — Analysis Report
日本語
コンディション概ね良好 — 通常の山岳安全対策を実施すること
English
Conditions generally good — Conduct standard mountain safety measures
Rishiri-zan is experiencing clear skies with excellent visibility exceeding 20 kilometers. However, the summit temperature is 3.1 degrees Celsius, with a perceived temperature of minus 0.5 degrees Celsius, a significant drop from the base's 12.5 degrees Celsius. Summit temperatures will remain around 3 to 4 degrees Celsius throughout the day, with wind speeds between 2.78 and 4.33 meters per second and gusts potentially exceeding 10 meters per second. Essential cold weather gear is mandatory.
There is no snow cover, and the ground is generally dry. However, shaded areas, north-facing slopes, and sheltered gullies may still be damp or frosty. Special caution is advised on the fragile volcanic scree terrain from the 9th station to the summit, as it can be slippery when wet. Crampons or microspikes are not necessary, but a waterproof and windproof outer layer, a mid-layer such as fleece, and a quick-drying base layer are essential. Gloves and a hat should also be carried.
The risk of hypothermia is present due to the low daytime temperatures and wind. While body temperature may be maintained during activity, it can drop quickly during breaks or periods of inactivity. Take frequent short breaks, refuel with snacks, and diligently manage your body temperature. The risk of lightning is low, but be cautious of losing balance due to strong gusts. Both the Oshidomari and Kutsugata courses involve steep volcanic scree slopes directly below the summit, requiring careful foot placement.
After 6 PM, the sky will become partly cloudy, and temperatures will drop below freezing. Winds will also pick up slightly at night, so avoid activity after sunset. While no significant alerts have been detected by the automated risk assessment, always be mindful of sudden changes in conditions due to the island's unique exposure to sea winds, and refrain from any overly ambitious undertakings.
There is no snow cover, and the ground is generally dry. However, shaded areas, north-facing slopes, and sheltered gullies may still be damp or frosty. Special caution is advised on the fragile volcanic scree terrain from the 9th station to the summit, as it can be slippery when wet. Crampons or microspikes are not necessary, but a waterproof and windproof outer layer, a mid-layer such as fleece, and a quick-drying base layer are essential. Gloves and a hat should also be carried.
The risk of hypothermia is present due to the low daytime temperatures and wind. While body temperature may be maintained during activity, it can drop quickly during breaks or periods of inactivity. Take frequent short breaks, refuel with snacks, and diligently manage your body temperature. The risk of lightning is low, but be cautious of losing balance due to strong gusts. Both the Oshidomari and Kutsugata courses involve steep volcanic scree slopes directly below the summit, requiring careful foot placement.
After 6 PM, the sky will become partly cloudy, and temperatures will drop below freezing. Winds will also pick up slightly at night, so avoid activity after sunset. While no significant alerts have been detected by the automated risk assessment, always be mindful of sudden changes in conditions due to the island's unique exposure to sea winds, and refrain from any overly ambitious undertakings.
山岳ガイド — Mountain Guide
概要 Overview
北海道北部、日本海に浮かぶ利尻島にそびえる標高1,721mの独立峰。「利尻富士」とも呼ばれる美しい山容で、海から一気にせり上がる姿は北海道百名山の象徴的存在。利尻礼文サロベツ国立公園の核心部。
特徴・地形 Features
海抜0mから山頂まで一気に登る独立峰のため、登山開始時は森林帯、中腹から低木帯・高山帯と植生が劇的に変化。山頂直下の脆い火山礫の急斜面が核心部。
ベストシーズン Best Season
6月下旬〜9月中旬。それ以外の時期は雪と寒気で本格冬山となる。海風の影響で気象変化が激しい。
主要ルート Main Routes
鴛泊コース(最一般的・標高差1,500m超)、沓形コース(中級者向け・崩落で通行止めも多い)。
注意点・危険箇所 Cautions
山頂直下の崩落地形での滑落事故が多発。9合目から山頂は脆い火山礫で踏み抜き注意。海風による濃霧・低温に備える。
アクセス Access
稚内空港・稚内港からフェリーで利尻島へ。鴛泊港から登山口までタクシーまたはバス。
※ 本ガイド情報は一般的な参考資料であり、最新の登山道状況・規制情報は各自治体・登山口の公式情報をご確認ください。