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Île de Batz wave buoy daily means for Jul 2025

Daily means from the Île de Batz wave buoy for Jul 2025, 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

1,460 wave-buoy observations covered all 31 days. Typical wave height was 2.9 ft (10th–90th percentile 1.6–6.1 ft), while mean peak wave period was 8.2 seconds (10th–90th percentile 6.1–10.2 seconds). Typical calculated wave power was approximately 2.4 kW/m (10th–90th percentile 0.7–13 kW/m), derived from significant wave height and energy period. 2 of 4,380 checked values (0%) were excluded by quality control. Across 4 comparable years, mean wave height was above the same-month mean of 2.6 ft and mean wave period was above the same-month mean of 8 seconds.

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

Typical Significant Wave Height

2.9ft
Mean: 3.3 ft
P10–P90: 1.6 — 6.1 ft
Recorded extremes

1 — 10.3 ft

Mean Observed Wave Period

8.2secs
P10–P90: 6.1 — 10.2secs
Recorded extremes

3.9 — 13.5secs

Typical Wave Power

Approximately 2.39kW/m
Mean: 4.47kW/m
P10–P90: 0.73 — 13.03kW/m
Recorded extremes

0.27 — 44.38kW/m

Calculated from significant wave height and energy period.

Typical Observed Wind

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

Available for 0 of 732 hourly samples

Mean Water Temperature

-°C
P10–P90: - — -°C

Available for 0 of 732 hourly samples

Compared With Previous Julys

Historical baseline from 5,952 observations across 4 years.

Wave Height
3.3ft
0.7ft above mean
Historical mean 2.592ft
Wave Period
8.2s
0.2s above mean
Historical mean 8s
Water Temperature
–
Not enough comparable data

Chart showing grouped wave observations for Île de Batz. 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 Île de Batz wave buoy

Île de Batz is a CANDHIS directional buoy off northern Brittany, within the French national sea-state observatory coordinated by Cerema. The station sits at the western entrance to the English Channel, where Atlantic swell rounds Brittany towards the exposed Finistère and Channel coasts.

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

Metrics are rows; days run left to right.
Île de Batz wave buoy daily means Jul 2025Last observation shown
Metric
Mean significant wave height (ft)3432567422222375322364242243333
Mean maximum wave height (ft)5544810116333235108433597353465554
Mean peak period (s)10767998877888910988871081067101110878
Mean average period (s)9666887666766798777687666898766
Mean period Tm02 (s)7555666555555676666566555676555
Mean peak wave directionWNWconcentration 100%NWconcentration 96%WNWconcentration 99%WNWconcentration 97%WNWconcentration 100%WNWconcentration 100%WNWconcentration 100%WNWconcentration 100%WNWconcentration 100%WNWconcentration 100%WNWconcentration 100%WNWconcentration 100%WNWconcentration 92%WNWconcentration 100%WNWconcentration 100%WNWconcentration 100%WNWconcentration 100%WNWconcentration 100%WNWconcentration 100%WNWconcentration 100%WNWconcentration 100%WNWconcentration 100%WNWconcentration 100%NWconcentration 97%WNWconcentration 97%WNWconcentration 100%WNWconcentration 100%WNWconcentration 100%WNWconcentration 100%WNWconcentration 100%WNWconcentration 100%
Mean directional spread (°)24.629.527.627.021.521.622.523.624.725.726.726.826.124.721.922.125.125.526.124.623.022.925.031.230.325.523.224.524.624.925.0
Mean water temperature(°C)-------------------------------

Swipe sideways to see more days.

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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