Portsmouth (USPTM) — marine weather & port guide
Portsmouth is a port in United States at 36°50.0′N 76°18.0′W. Today (Aug 3): SSW wind 6–8 kn, waves 2.2–2.4 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 | 36°50.0′N 76°18.0′W |
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| UN/LOCODE | USPTM |
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| Harbor size | Small |
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| Harbor type | River natural harbor |
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| Shelter | Excellent |
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| Channel depth | 13 m |
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| Anchorage depth | 13 m |
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| Tide range | 1 m |
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| Pilotage | Compulsory |
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| Time zone | America/New_York |
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10-day marine forecast — Portsmouth
| Date | Wind | Gusts | Waves |
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| SSW 6–8 kn | 18 kn | 2.2–2.4 m |
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| SW 0–7 kn | 15 kn | 1.3–2.0 m |
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| S 3–6 kn | 16 kn | 1.0–1.1 m |
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| SSW 4–8 kn | 19 kn | 0.9–1.1 m |
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| SSW 5–7 kn | 12 kn | 0.9–1.0 m |
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| SSW 5–7 kn | 9 kn | 1.1–1.1 m |
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| SSW 6–7 kn | 9 kn | 1.1–1.1 m |
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| WSW 4–4 kn | 10 kn | 0.8–0.8 m |
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| SW 5–5 kn | 12 kn | 0.8–0.8 m |
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| NW 4–4 kn | 11 kn | 0.9–0.9 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 Portsmouth right now?
As of the ECMWF IFS run 2026-08-03 12z: SSW wind 6–8 kn, waves 2.2–2.4 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 Portsmouth?
Portsmouth is classed as a small harbor (river natural harbor), with excellent shelter in the NGA World Port Index.
How deep is the approach to Portsmouth?
Per the NGA World Port Index, the entrance channel carries about 13 m and anchorage depths run about 13 m. Verify against current official charts before entry.