Soma (JPSOM) — marine weather & port guide
Soma is a port in Japan at 37°47.0′N 140°55.0′E. Today (Aug 3): NE wind 13–17 kn, waves 3.1–3.3 m, from the ECMWF IFS run 2026-08-03 12z. The live chart on this page shows current conditions and plans weather-optimized departures from this harbor.
Port facts (NGA World Port Index)| Position | 37°47.0′N 140°55.0′E |
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| UN/LOCODE | JPSOM |
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| Harbor size | Very small |
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| Harbor type | Coastal breakwater harbor |
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| Shelter | Poor |
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| Channel depth | 6 m |
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| Tide range | 0 m |
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| Pilotage | Advisable |
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| Time zone | Asia/Tokyo |
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10-day marine forecast — Soma
| Date | Wind | Gusts | Waves |
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| NE 13–17 kn | 19 kn | 3.1–3.3 m |
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| NE 10–14 kn | 18 kn | 3.0–3.4 m |
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| NE 5–10 kn | 14 kn | 2.5–2.8 m |
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| SSE 4–9 kn | 11 kn | 2.4–2.5 m |
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| S 8–12 kn | 14 kn | 2.0–2.2 m |
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| SSE 2–10 kn | 12 kn | 2.0–2.0 m |
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| NNE 10–18 kn | 22 kn | 2.1–2.8 m |
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| N 23–23 kn | 33 kn | 3.9–3.9 m |
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| SSW 11–11 kn | 14 kn | 2.2–2.2 m |
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| W 1–1 kn | 7 kn | 1.5–1.5 m |
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Forecast from the ECMWF IFS model run , waves from ECMWF WAM. Updated with each model cycle; the live chart below recalculates for your departure time and vessel.
Frequently asked
How is the weather at Soma right now?
As of the ECMWF IFS run 2026-08-03 12z: NE wind 13–17 kn, waves 3.1–3.3 m. The 10-day outlook is in the forecast table on this page and updates with each model cycle.
How big is the harbor at Soma?
Soma is classed as a very small harbor (coastal breakwater harbor), with poor shelter in the NGA World Port Index.
How deep is the approach to Soma?
Per the NGA World Port Index, the entrance channel carries about 6 m. Verify against current official charts before entry.