Waves in São Martinho Grande
Hourly wave forecast for 7 days · updated today, Thursday, October 29, at 1:53 am (GMT-1)- Sea state
- Slight · Douglas 3
- Period
- 10.3 s · SW
- Swell
- 2.2 ft · 9 s
- Highest expected
- 5.7 ft
Today the sea at São Martinho Grande is slight: 2.9 ft waves with a period of 10.3 s from the southwest. The swell, 2.2 ft at 9 s, comes from the south-southwest.
Wave height, next 7 days
Significant height: the average of the highest third of the waves, what an observer would estimate by eye. Swell: waves arriving from far away, longer.
The waves you may find today
- Most common1.4 ft
- Significant2.9 ft
- Highest expected5.7 ft
One wave in seven is higher than the significant height, and about 3 times a day one reaches 5.7 ft. Before heading out, expect waves of up to 5.7 ft.
The Douglas sea state scale
| Degree | Name | Wave height |
|---|---|---|
| 0 | Calm (glassy) | 0 |
| 1 | Calm (rippled) | 0.0 ft–0.3 ft |
| 2 | Smooth | 0.3 ft–1.6 ft |
| 3 | Slight · today | 1.6 ft–4.1 ft |
| 4 | Moderate | 4.1 ft–8.2 ft |
| 5 | Rough | 8.2 ft–13.1 ft |
| 6 | Very rough | 13.1 ft–19.7 ft |
Waves day by day
| Day | Max wave | Sea state | Direction | Max period | Swell | Max wind |
|---|---|---|---|---|---|---|
| Today | 3.0 ft | Slight | NW | 10 s | 2.2 ft SSW | 12 mph N |
| Fri 30 | 3.0 ft | Slight | NE | 8 s | 1.8 ft N | 11 mph N |
| Sat 31 | 2.4 ft | Slight | SE | 10 s | 1.3 ft ESE | 7 mph N |
| Sun 1 | 2.6 ft | Slight | S | 11 s | 1.8 ft S | 6 mph NNE |
| Mon 2 | 2.9 ft | Slight | SSW | 11 s | 2.2 ft S | 8 mph N |
| Tue 3 | 2.9 ft | Slight | S | 11 s | 2.3 ft S | 9 mph N |
| Wed 4 | 2.8 ft | Slight | SSE | 10 s | 2.1 ft S | 8 mph NNE |
Today, every 3 hours
| Time | 12:00 am | 3:00 am | 6:00 am | 9:00 am | 12:00 pm | 3:00 pm | 6:00 pm | 9:00 pm |
|---|---|---|---|---|---|---|---|---|
| Waves | 2.9 ft | 2.9 ft | 2.9 ft | 2.9 ft | 3.0 ft | 3.0 ft | 3.0 ft | 3.0 ft |
| Period | 10.3 s | 10.4 s | 10.2 s | 9.7 s | 8.8 s | 8.3 s | 8.1 s | 7.9 s |
| Direction | SW | SW | WSW | W | NW | NNE | NE | NE |
| Swell | 2.2 ft · 8 s | 2.2 ft · 9 s | 2.0 ft · 9 s | 1.9 ft · 9 s | 2.0 ft · 8 s | 1.9 ft · 8 s | 1.8 ft · 8 s | 1.8 ft · 8 s |
| Wind (mph) | 7 NNW | 9 NNW | 8 NNW | 8 NNE | 12 NE | 10 NE | 9 N | 8 N |
Questions about the waves in São Martinho GrandeQuestions
How are the waves today in São Martinho Grande?
Slight (2.9 ft with a period of 10.3 s from the southwest). The highest wave to expect is around 5.7 ft.
Which day will have the biggest waves this week?
Thursday 29, with waves up to 3.0 ft (slight).
What is the wave period?
The time, in seconds, between two crests. With long periods (over 10 s) waves come from far away, are cleaner and break harder; with short periods they are wind waves, choppier.
What is significant wave height?
The average of the highest third of the waves. One in seven is higher and, a few times a day, one comes in at almost double: today, about 5.7 ft.
More about São Martinho Grande today
Waves near São Martinho Grande
- Porto Gouveia 3.5 ft · 11 s · 6.5 mi
- Santa Cruz 3.6 ft · 10 s · 14 mi
- Ribeira da Barca 4.1 ft · 11 s · 19 mi
Only places with a different forecast: spots a few miles apart share the same model cell and wouldn't add anything.
Learn more
Waves: Open-Meteo with Météo-France (MFWAM, up to 10 days) and ECMWF WAM, CC BY 4.0; wave grid point 3.9 mi away. Near the shore, the seabed and the shape of the coast change the waves.
Forecast from Open-Meteo (CC BY 4.0) with models from ECMWF, NOAA, Météo-France, DWD, Copernicus Marine and CAMS. Updated at 1:53 am (local time).
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