San Antonio marine weather forecast
San Antonio (CLSAI) is a port in Chile at 33°36.0′S 71°36.0′W. Today (Sep 15): SSW wind 10–19 kn, waves 1.6–2.1 m, from the ECMWF IFS run 2026-09-15 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 | 33°36.0′S 71°36.0′W |
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| UN/LOCODE | CLSAI |
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| Harbor size | Small |
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| Harbor type | Coastal breakwater harbor |
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| Shelter | Good |
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| Channel depth | 23 m |
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| Anchorage depth | 23 m |
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| Tide range | 4 m |
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| Pilotage | Compulsory |
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| Time zone | America/Santiago |
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Facilities & services (NGA World Port Index)| Tugs | Assistance available |
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| Supplies | Fuel oil, diesel, water, provisions |
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| Repairs | Moderate |
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| Medical facilities | Available |
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10-day marine forecast — San Antonio
| Date | Wind | Gusts | Waves |
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| SSW 10–19 kn | 22 kn | 1.6–2.1 m |
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| S 12–18 kn | 23 kn | 1.5–1.6 m |
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| S 2–17 kn | 22 kn | 1.4–1.8 m |
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| SE 3–8 kn | 11 kn | 1.3–1.4 m |
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| NNW 6–12 kn | 15 kn | 1.2–1.3 m |
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| NNE 11–13 kn | 16 kn | 1.2–1.3 m |
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| N 9–9 kn | 11 kn | 1.6–1.6 m |
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| SSW 21–21 kn | 29 kn | 2.2–2.2 m |
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| S 14–14 kn | 24 kn | 1.8–1.8 m |
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| S 12–12 kn | 18 kn | 1.0–1.0 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 21 kn on Sep 22. The highest modeled significant wave height is 2.2 m on Sep 22. Compare the dated model run with official forecasts and warnings before departure.
Frequently asked
How is the weather at San Antonio right now?
As of the ECMWF IFS run 2026-09-15 00z: SSW wind 10–19 kn, waves 1.6–2.1 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 San Antonio?
San Antonio is classed as a small harbor (coastal breakwater harbor), with good shelter in the NGA World Port Index.
How deep is the approach to San Antonio?
Per the NGA World Port Index, the entrance channel carries about 23 m and anchorage depths run about 23 m. Verify against current official charts before entry.
What restricts entry to San Antonio?
Entry is affected by tidal windows, heavy swell. Check the live forecast on this page and official notices before approach.