TidePlanet

Waves in Río San Juan

Hourly wave forecast for 7 days · updated today, Wednesday, October 28, at 10:54 pm (AST)
Now · significant height 4.2 ft
Sea state
Moderate · Douglas 4
Period
9.6 s · NNE
Swell
3.8 ft · 9 s
Highest expected
8.4 ft

Today the sea at Río San Juan is moderate: 4.2 ft waves with a period of 9.6 s from the north-northeast. The swell, 3.8 ft at 9 s, comes from the north-northeast.

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 common2.1 ft
  • Significant4.2 ft
  • Highest expected8.4 ft

One wave in seven is higher than the significant height, and about 3 times a day one reaches 8.4 ft. Before heading out, expect waves of up to 8.4 ft.

The Douglas sea state scale

DegreeNameWave height
0 Calm (glassy) 0
1 Calm (rippled) 0.0 ft–0.3 ft
2 Smooth 0.3 ft–1.6 ft
3 Slight 1.6 ft–4.1 ft
4 Moderate · today 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 4.9 ft Moderate NNE 11 s 4.6 ft N 8 mph SSE
Thu 29 4.1 ft Moderate NE 10 s 3.7 ft NNE 8 mph SE
Fri 30 3.2 ft Slight NE 9 s 2.8 ft NNE 5 mph SSE
Sat 31 3.0 ft Slight NE 9 s 2.8 ft NNE 7 mph ENE
Sun 1 3.0 ft Slight NE 8 s 2.7 ft NNE 6 mph SE
Mon 2 3.4 ft Slight NE 8 s 3.1 ft NNE 6 mph SSE
Tue 3 3.1 ft Slight NE 8 s 2.8 ft NNE 8 mph SSE

Today, every 3 hours

Time 12:00 am3:00 am6:00 am9:00 am12:00 pm3:00 pm6:00 pm9:00 pm
Waves 4.6 ft4.7 ft4.8 ft4.9 ft4.7 ft4.6 ft4.5 ft4.3 ft
Period 10.7 s10.8 s10.8 s10.7 s10.5 s10.3 s10.0 s9.7 s
Direction NNENNENNENNENNENNENNENNE
Swell 4.3 ft · 10 s4.4 ft · 10 s4.5 ft · 9 s4.6 ft · 9 s4.5 ft · 9 s4.3 ft · 9 s4.1 ft · 9 s3.9 ft · 9 s
Wind (mph) 1 SE3 S3 SSW4 SSE8 SSE6 SE5 SSE5 SSE

Previous days

The waves over the last 14 days. Tap a day to see it hour by hour.

DayMax wavePeriodSwell
Tue 27 6.9 ft NNE12 s6.6 ft NNE
Mon 26 7.2 ft NNE12 s6.9 ft N
Sun 25 5.2 ft NNE11 s4.6 ft N
Sat 24 5.2 ft NNE11 s4.9 ft N
Fri 23 6.2 ft N12 s5.9 ft N
Thu 22 5.9 ft N12 s5.6 ft N
Wed 21 5.6 ft N11 s5.6 ft N
Show all 14 days
DayMax wavePeriodSwell
Tue 20 6.9 ft N13 s6.6 ft N
Mon 19 4.6 ft NE12 s4.3 ft NE
Sun 18 3.3 ft NE9 s2.6 ft NE
Sat 17 3.3 ft NE10 s2.6 ft NNE
Fri 16 3.0 ft ENE8 s1.6 ft ENE
Thu 15 2.6 ft ENE8 s2.3 ft ENE
Wed 14 3.3 ft NE8 s3.3 ft NE

These are the models at the start of each day (ECMWF and GFS; waves from Météo-France), not readings from a weather station: there can be differences at specific spots.

Questions about the waves in Río San JuanQuestions

How are the waves today in Río San Juan?

Moderate (4.2 ft with a period of 9.6 s from the north-northeast). The highest wave to expect is around 8.4 ft.

Which day will have the biggest waves this week?

Wednesday 28, with waves up to 4.9 ft (moderate).

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 8.4 ft.

More about Río San Juan today

Waves near Río San Juan

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 11 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 10:54 pm (local time).

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