Japan Prefecture Rust Risk Map
Where a truck spent its life determines its rust profile. Sea-of-Japan and northern prefectures see months of road salt; central and Kyushu prefectures rarely do.
Legend
🔴
High (8–10)
Months of road salt and freeze-thaw — inspect frame and underbody carefully.
🟡
Medium (4–7)
Intermittent salt — inspect if sourced from mountain counties.
🟢
Low (1–3)
Mild winters and minimal salt — typically clean undercarriages.
| Prefecture | Risk | Reason | Key Inspection Points |
|---|---|---|---|
| Hokkaido 北海道 | 🔴 high · 10 | Severe winters, heavy road salt for months, frequent freeze-thaw cycles. | Frame rails, bed floor, suspension arms, brake and fuel lines |
| Niigata 新潟 | 🔴 high · 10 | Among Japan's highest snowfall regions; salt applied for months. | Frame rails, suspension, brake and fuel lines, fuel tank straps |
| Aomori 青森 | 🔴 high · 9 | Long winters with sustained salt use; coastal exposure. | Frame, undercarriage, brake lines |
| Akita 秋田 | 🔴 high · 9 | Sea of Japan winters bring sustained salt and humidity. | Frame rails, brake lines, fuel tank straps |
| Yamagata 山形 | 🔴 high · 9 | Heavy snowfall, prolonged salt exposure on mountain passes. | Frame, suspension components, exhaust system |
| Toyama 富山 | 🔴 high · 9 | Sea of Japan coast with heavy winter salt. | Frame, exhaust, brake lines |
| Iwate 岩手 | 🔴 high · 8 | Cold winters with regular salt application on mountain routes. | Frame, suspension mounts, brake lines |
| Ishikawa 石川 | 🔴 high · 8 | Coastal salt-laden winters along the Sea of Japan. | Underbody and frame |
| Fukui 福井 | 🔴 high · 8 | Heavy snow plus coastal salt exposure. | Frame and suspension components |
| Fukushima 福島 | 🟡 medium · 7 | Mountainous interior sees significant winter salt; coastal areas lower risk. | Underbody, brake lines |
| Miyagi 宮城 | 🟡 medium · 6 | Moderate winter salt, coastal areas hit by 2011 tsunami salt residue. | Underbody, frame near rear shackles |
| Gunma 群馬 | 🟡 medium · 6 | Mountain passes receive sustained winter salt. | Frame and suspension if sourced from northern Gunma |
| Nagano 長野 | 🟡 medium · 6 | Mountain prefectures vary — highland passes see winter salt. | Frame if sourced from mountain counties |
| Tochigi 栃木 | 🟡 medium · 5 | Northern mountain areas see winter salt; flatlands lower. | Underbody if from mountainous county |
| Gifu 岐阜 | 🟡 medium · 5 | Northern Gifu mountainous, southern flatlands lower risk. | Standard inspection unless from northern Gifu |
| Tottori 鳥取 | 🟡 medium · 5 | Sea of Japan coast with moderate winter salt. | Underbody and frame |
| Shimane 島根 | 🟡 medium · 5 | Coastal salt and winter exposure. | Underbody and frame |
| Ibaraki 茨城 | 🟢 low · 3 | Mild winters, limited salt use on roads. | Standard inspection |
| Yamanashi 山梨 | 🟢 low · 3 | Inland mountains with relatively dry winters. | Standard inspection |
| Shiga 滋賀 | 🟢 low · 3 | Lake Biwa moderates winters; limited salt use. | Standard inspection |
| Yamaguchi 山口 | 🟢 low · 3 | Mild south, mountainous north sees some winter salt. | Standard inspection |
| Saitama 埼玉 | 🟢 low · 2 | Mild winters, limited salt application. | Standard inspection |
| Chiba 千葉 | 🟢 low · 2 | Mild coastal climate. | Standard inspection |
| Shizuoka 静岡 | 🟢 low · 2 | Mild Pacific coast climate. | Standard inspection |
| Mie 三重 | 🟢 low · 2 | Mild Pacific climate. | Standard inspection |
| Kyoto 京都 | 🟢 low · 2 | Mild basin climate. | Standard inspection |
| Hyogo 兵庫 | 🟢 low · 2 | Southern coastal mild; northern mountain higher. | Standard inspection |
| Nara 奈良 | 🟢 low · 2 | Mild interior basin. | Standard inspection |
| Okayama 岡山 | 🟢 low · 2 | Mild inland Setouchi climate. | Standard inspection |
| Hiroshima 広島 | 🟢 low · 2 | Mild Setouchi coast. | Standard inspection |
| Tokushima 徳島 | 🟢 low · 2 | Mild Pacific coast. | Standard inspection |
| Ehime 愛媛 | 🟢 low · 2 | Mild Setouchi coast. | Standard inspection |
| Kochi 高知 | 🟢 low · 2 | Warm Pacific coast, humid but low salt. | Standard inspection |
| Fukuoka 福岡 | 🟢 low · 2 | Mild Kyushu climate. | Standard inspection |
| Nagasaki 長崎 | 🟢 low · 2 | Mild coastal Kyushu; minor coastal salt. | Standard inspection |
| Okinawa 沖縄 | 🟢 low · 2 | No snow or road salt, but heavy coastal salt-air corrosion. | Surface rust on exposed steel from sea-air exposure |
| Tokyo 東京 | 🟢 low · 1 | Urban heat island, minimal road salt. | Standard inspection |
| Kanagawa 神奈川 | 🟢 low · 1 | Mild coastal climate, low salt use. | Standard inspection |
| Aichi 愛知 | 🟢 low · 1 | Mild climate, low road-salt use — auction houses concentrated here. | Standard inspection |
| Osaka 大阪 | 🟢 low · 1 | Urban, mild winters, minimal road salt. | Standard inspection |
| Wakayama 和歌山 | 🟢 low · 1 | Mild Pacific coast. | Standard inspection |
| Kagawa 香川 | 🟢 low · 1 | Driest prefecture in Japan; minimal salt. | Standard inspection |
| Saga 佐賀 | 🟢 low · 1 | Mild Kyushu climate. | Standard inspection |
| Kumamoto 熊本 | 🟢 low · 1 | Mild Kyushu inland climate. | Standard inspection |
| Oita 大分 | 🟢 low · 1 | Mild Kyushu climate. | Standard inspection |
| Miyazaki 宮崎 | 🟢 low · 1 | Warm Pacific Kyushu. | Standard inspection |
| Kagoshima 鹿児島 | 🟢 low · 1 | Warm southern Kyushu; volcanic ash exposure in some areas. | Check for volcanic-ash exposure on body and seals |
Pro tip
The auction sheet shows the seller's prefecture. Ask your exporter to filter for Aichi, Osaka, Kanagawa, or Kagawa stock when frame condition is a priority — these prefectures rarely see road salt and undercarriages tend to be clean.