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Plateau du Four wave buoy daily means for Jul 2026

Daily means from the Plateau du Four wave buoy for Jul 2026, including available wave height, period, direction, wind and sea temperature data.

Last observation shown

Data available:  to 

Monthly means for

Latest

Period Summary

Programmatically generated summary. Hog Says

1,487 wave-buoy observations covered all 31 days. Typical wave height was 1.3 ft (10th–90th percentile 0.8–3 ft), while mean average of more than one wave period type was 4.9 seconds (10th–90th percentile 3.1–7.4 seconds). Typical calculated wave power was approximately 3.5 kW/m, derived from significant wave height and energy period. Mean water temperature was 20.7°C (10th–90th percentile 18.5–22.8°C). 1 of 5,518 checked values (0%) were excluded by quality control. Across 16 comparable years, mean wave height was below the same-month mean of 2.8 ft and mean wave period was below the same-month mean of 7.4 seconds.

Generated only from the observations and comparisons shown on this page.

Typical Significant Wave Height

1.3ft
Mean: 1.6 ft
P10–P90: 0.8 — 3 ft
Recorded extremes

0.7 — 4.6 ft

Mean Observed Wave Period

4.9secs
P10–P90: 3.1 — 7.4secs
Recorded extremes

2.4 — 9.4secs

Typical Wave Power

Approximately 3.48kW/m
Mean: 3.48kW/m
P10–P90: 3.48 — 3.48kW/m
Recorded extremes

3.42 — 3.54kW/m

Calculated from significant wave height and energy period.

Available for 1 of 744 hourly samples with wave power

Typical Observed Wind

-, -mph
Mean: - mph
P10–P90: - — - mph

Available for 0 of 744 hourly samples

Mean Water Temperature

20.7°C
P10–P90: 18.5 — 22.8°C
Recorded extremes

17.3 — 25.5°C

Available for 670 of 744 hourly samples

Compared With Previous Julys

Historical baseline from 23,171 observations across 16 years.

Wave Height
1.6ft
1.2ft below mean
Historical mean 2.789ft
Wave Period
4.9s
2.5s below mean
Historical mean 7.4s
Water Temperature
20.7°C
Not enough comparable data

Chart showing grouped wave observations for Plateau du Four. Use the table on this page for a text version of the same measurements. To open hourly observations, use a linked day name in the table.

About Plateau du Four wave buoy

Plateau du Four is a CANDHIS station associated with the SEM-REV offshore test site off Loire-Atlantique. Located near a shallow offshore bank west of Le Croisic, it supplies environmental context for marine-energy research and for an exposed sector between the Loire estuary and southern Brittany.

Its current data source reports wave height, wave period, wave direction, directional spread and sea temperature.

Metrics are rows; days run left to right.
Plateau du Four wave buoy daily means Jul 2026Last observation shown
Metric
Mean significant wave height (ft)3322111111112111112221112331112
Mean maximum wave height (ft)6533211222224222224432224642223
Mean peak period (s)5------------------------------
Mean average period (s)7666668555644555543433334556754
Mean period Tm02 (s)4------------------------------
Mean peak wave directionWconcentration 100%Wconcentration 100%Wconcentration 100%Wconcentration 100%Wconcentration 92%Wconcentration 68%Wconcentration 100%SWconcentration 61%Wconcentration 64%Wconcentration 92%Wconcentration 100%NNWconcentration 37%Wconcentration 32%WSWconcentration 98%Wconcentration 96%WSWconcentration 99%WSWconcentration 97%NWconcentration 56%NEconcentration 98%NEconcentration 99%NEconcentration 98%Nconcentration 36%NEconcentration 45%NEconcentration 57%NWconcentration 76%Wconcentration 99%Wconcentration 100%WSWconcentration 57%Wconcentration 100%Wconcentration 92%WNWconcentration 88%
Mean directional spread (°)19.320.723.022.326.430.229.628.225.827.123.228.426.827.024.226.727.630.628.128.029.130.229.530.927.122.124.432.030.827.927.4
Mean water temperature(°C)20.619.719.519.519.821.222.022.322.222.522.622.721.721.922.022.222.421.618.517.817.918.519.319.118.719.019.220.020.620.420.3

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Wave metric colour key

Colours move through the scale as each number increases. They do not by themselves mean that conditions are good, safe or suitable for you.

Wave & swell height0–40+ ft
Wave & swell period0–22+ s
Wind speed0–75 mph

The displayed numbers remain the source of truth; colour is an additional visual cue.

What does buoy wave power mean?

kW/m means kilowatts of wave power per metre of wave crest. It describes the rate at which the observed sea state carries energy past the buoy.

Unlike the shore-directed forecast value, buoy wave power is the total power at the observation point. It is not projected towards a particular beach and does not predict breaking wave height.

In deep water, wave power can be calculated with:

P is approximately 0.49 times significant wave height squared times wave energy period.

P is power in kW/m, Hs is significant wave height in metres, and Te is wave energy period in seconds.

  • Provider-reported power is used when available.
  • Otherwise, a value is calculated only when both significant height and a genuine energy period are available. The ≈ symbol marks calculated values.
  • A dash is shown instead of substituting peak, Tm02, zero-crossing or other period measurements.
  • Daily and monthly figures use the mean of hourly-normalized observation power values; they are not calculated from mean height and period.

Wave direction, spectrum, water depth and local bathymetry still matter. Wave power is best read alongside height, period and direction rather than as a standalone surf-quality score.

The observation data displayed on this page is from the Cerema CANDHIS coastal wave observatory.

Learn how SurfHog combines, checks and summarizes observations in the data and methodology notes.

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