Portsmouth marine weather forecast
Portsmouth (USPTM) is a port in United States at 36°50.0′N 76°18.0′W. Today (Sep 16): ENE wind 1–4 kn, waves 1.2–1.6 m, from the ECMWF IFS run 2026-09-16 00z. 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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Facilities & services (NGA World Port Index)| Tugs | Assistance and salvage available |
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| Supplies | Fuel oil, diesel, water, provisions |
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| Repairs | Major (hull, machinery, electrical) |
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| Medical facilities | Available |
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10-day marine forecast — Portsmouth
| Date | Wind | Gusts | Waves |
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| ENE 1–4 kn | 12 kn | 1.2–1.6 m |
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| S 2–5 kn | 10 kn | 0.9–1.1 m |
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| SSW 4–6 kn | 13 kn | 0.9–0.9 m |
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| NE 5–7 kn | 18 kn | 0.8–1.5 m |
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| ESE 1–5 kn | 6 kn | 1.3–1.7 m |
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| SSE 3–6 kn | 8 kn | 1.0–1.1 m |
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| NNE 1–1 kn | 1 kn | 1.0–1.0 m |
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| NNE 8–8 kn | 14 kn | 0.9–0.9 m |
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| NE 13–13 kn | 31 kn | 4.7–4.7 m |
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| NE 9–9 kn | 28 kn | 4.0–4.0 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.
What to watch in the forecast
Across the loaded 10-day outlook, the strongest daily modeled wind reaches 13 kn on Sep 24. The highest modeled significant wave height is 4.7 m on Sep 24. Compare the dated model run with official forecasts and warnings before departure.
Frequently asked
How is the weather at Portsmouth right now?
As of the ECMWF IFS run 2026-09-16 00z: ENE wind 1–4 kn, waves 1.2–1.6 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.