Waves in Portsmouth

Hourly wave forecast for 7 days · updated today, Wednesday, October 28, at 5:59 pm (EDT)

Now · significant height 1.5 ft

Sea state: Smooth · Douglas 2
Period: 7.9 s · ESE
Swell: 1.2 ft · 8 s
Highest expected: 3.1 ft

Today the sea at Portsmouth is smooth: 1.5 ft waves with a period of 7.9 s from the east-southeast. The swell, 1.2 ft at 8 s, comes from the east-southeast.

Wave height, next 7 days

1.02.03.0 ft 2.2 ft Now

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 common0.8 ft
Significant1.5 ft
Highest expected3.1 ft

One wave in seven is higher than the significant height, and about 3 times a day one reaches 3.1 ft. Before heading out, expect waves of up to 3.1 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 · today	0.3 ft–1.6 ft
3	Slight · week peak	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	2.2 ft	Slight	E	8 s	1.6 ft ESE	5 mph W
Thu 29	1.9 ft	Slight	SE	7 s	1.3 ft ESE	9 mph SW
Fri 30	1.8 ft	Slight	SW	5 s	1.2 ft SE	12 mph W
Sat 31	1.5 ft	Smooth	NNW	7 s	0.5 ft ESE	7 mph NW
Sun 1	0.7 ft	Smooth	ESE	9 s	0.5 ft SE	5 mph WSW
Mon 2	1.0 ft	Smooth	ESE	10 s	1.0 ft ESE	5 mph WSW
Tue 3	1.3 ft	Smooth	ESE	10 s	1.0 ft E	6 mph ENE

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	1.8 ft	2.0 ft	2.2 ft	2.0 ft	1.9 ft	1.7 ft	1.5 ft	1.4 ft
Period	8.4 s	7.2 s	7.1 s	7.3 s	7.5 s	7.7 s	7.9 s	7.7 s
Direction	E	E	E	E	E	E	ESE	ESE
Swell	1.4 ft · 9 s	1.5 ft · 9 s	1.6 ft · 8 s	1.5 ft · 8 s	1.5 ft · 8 s	1.4 ft · 8 s	1.2 ft · 8 s	1.2 ft · 8 s
Wind (mph)	5 N	4 N	4 NNW	5 NNW	0 S	4 S	4 S	5 SSW

Previous days

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

Day	Max wave	Period	Swell
Tue 27	2.0 ft E	9 s	1.6 ft ENE
Mon 26	2.0 ft ESE	10 s	2.0 ft ESE
Sun 25	2.3 ft E	11 s	2.0 ft E
Sat 24	3.6 ft E	10 s	3.3 ft E
Fri 23	5.2 ft ENE	9 s	5.2 ft ENE
Thu 22	6.9 ft E	9 s	6.6 ft E
Wed 21	6.6 ft E	8 s	5.6 ft E

Show all 14 days

Day	Max wave	Period	Swell
Tue 20	5.2 ft ESE	9 s	4.9 ft ESE
Mon 19	2.6 ft ESE	9 s	2.6 ft ESE
Sun 18	1.3 ft E	9 s	1.0 ft ESE
Sat 17	2.3 ft N	6 s	1.6 ft SE
Fri 16	2.6 ft SE	10 s	2.3 ft SE
Thu 15	2.3 ft E	9 s	1.6 ft E
Wed 14	4.3 ft E	7 s	3.9 ft E

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 PortsmouthQuestions

How are the waves today in Portsmouth?

Smooth (1.5 ft with a period of 7.9 s from the east-southeast). The highest wave to expect is around 3.1 ft.

Which day will have the biggest waves this week?

Wednesday 28, with waves up to 2.2 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 3.1 ft.

More about Portsmouth today

Waves near Portsmouth

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 8.6 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 5:59 pm (local time).

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