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Brittany wave buoy daily means for Sep 2025

Daily means from the Brittany wave buoy for Sep 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

718 wave-buoy observations covered all 30 days. Wave-height and wave-period data were unavailable. Typical wind was 18.4 mph (10th–90th percentile 8.1–28.8 mph) and mean water temperature was 17.5°C (10th–90th percentile 17–18.1°C). All 2,154 checked values passed quality control.

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

Typical Wave Height

-ft
Mean: - ft
P10–P90: - — - ft

Available for 0 of 718 hourly samples

Mean Wave Period

-secs
P10–P90: - — -secs

Available for 0 of 718 hourly samples

Mean Water Temperature

17.5°C
P10–P90: 17 — 18.1°C
Recorded extremes

16.8 — 18.4°C

Typical Wind

N, 18.4mph
Mean: 18.7 mph
P10–P90: 8.1 — 28.8 mph
Recorded extremes

1.2 — 34.5 mph

Circular concentration: 100%

Compared With Previous Septembers

Historical baseline from 10,299 observations across 15 years.

Wave Height
–
Not enough comparable data
Historical mean 7ft
Wave Period
–
Not enough comparable data
Historical mean 6.7s
Water Temperature
17.5°C
0.6°C below mean
Historical mean 18.1°C

Chart showing grouped wave observations for Brittany. 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 Brittany wave buoy

Brittany buoy (WMO 62163) is maintained jointly by the UK Met Office and Météo-France in the Bay of Biscay. Its exposed position west of Brittany monitors Atlantic conditions approaching western France and the western entrance to the English Channel. The international feed can include wind, pressure, temperature and wave observations when available.

Metrics are rows; days run left to right.
Brittany wave buoy daily means Sep 2025Last observation shown
Metric
Mean wave height (ft)------------------------------
Mean observed period(s)------------------------------
Mean wave power(kW/m)------------------------------
Mean wind directionNconcentration 100%Nconcentration 100%Nconcentration 100%Nconcentration 100%Nconcentration 100%Nconcentration 100%Nconcentration 100%Nconcentration 100%Nconcentration 100%Nconcentration 100%Nconcentration 100%Nconcentration 100%Nconcentration 100%Nconcentration 100%Nconcentration 100%Nconcentration 100%Nconcentration 100%Nconcentration 100%Nconcentration 100%Nconcentration 100%Nconcentration 100%Nconcentration 100%Nconcentration 100%Nconcentration 100%Nconcentration 100%Nconcentration 100%Nconcentration 100%Nconcentration 100%Nconcentration 100%Nconcentration 100%
Mean wind speed (mph)232929211121191722272723192526162117162229231181015151344
Mean water temperature(°C)18.318.218.217.917.817.917.917.817.717.717.817.717.617.417.217.116.917.117.317.417.317.017.017.117.217.217.016.917.217.2

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.

Which wave period is shown?

The table shows the best period measurement supplied for each observation. It is not necessarily the energy period used to calculate wave power.

Tp
Peak period: the period at the strongest spectral peak.
Tavg
The provider's average wave period.
Tm02
A mean period calculated from the wave spectrum.
Tz
Mean zero-crossing period.
Reported
A legacy value whose period type was not recorded.
Mixed
A daily or monthly mean containing more than one period type.

Wave power needs a genuine energy period (Te). SurfHog does not substitute Tp, Tavg, Tm02 or Tz when Te is missing.

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 UK Met Office.

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