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Les Pierres Noires wave buoy monthly means for 2020

Monthly means from the Les Pierres Noires wave buoy for 2020, including available wave height, period, direction, wind and sea temperature data.

Last observation shown

Data available:  to 

Latest

Period Summary

Programmatically generated summary. Hog Says

17,568 wave-buoy observations covered all 366 days. Typical wave height was 5.4 ft (10th–90th percentile 2.4–13.9 ft), while mean average of more than one wave period type was 10.4 seconds (10th–90th percentile 7.4–13.3 seconds). Typical calculated wave power was approximately 11.7 kW/m (10th–90th percentile 1.9–91.9 kW/m), derived from significant wave height and energy period. 66 of 52,701 checked values (0.1%) were excluded by quality control.

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

Typical Significant Wave Height

5.4ft
Mean: 7.1 ft
P10–P90: 2.4 — 13.9 ft
Recorded extremes

0.8 — 27.3 ft

Mean Observed Wave Period

10.4secs
P10–P90: 7.4 — 13.3secs
Recorded extremes

2.6 — 21.3secs

Available for 8,780 of 8,784 hourly samples

Typical Wave Power

Approximately 11.74kW/m
Mean: 33.29kW/m
P10–P90: 1.85 — 91.86kW/m
Recorded extremes

0.18 — 399.45kW/m

Calculated from significant wave height and energy period.

Available for 8,783 of 8,784 hourly samples with wave power

Typical Observed Wind

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

Available for 0 of 8,784 hourly samples

Mean Water Temperature

-°C
P10–P90: - — -°C

Available for 0 of 8,784 hourly samples

Chart showing grouped wave observations for Les Pierres Noires. Use the table on this page for a text version of the same measurements. To open daily observations, use a linked month name in the table.

About Les Pierres Noires wave buoy

Les Pierres Noires is a CANDHIS directional buoy west of Brittany, maintained through the French national sea-state observatory and its scientific and maritime partners. Its position near the offshore reef and lighthouse represents fully exposed Atlantic conditions approaching the Iroise Sea and western Brittany.

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

Metrics are rows; months run left to right.
Les Pierres Noires wave buoy monthly means 2020Last observation shown
Metric
Mean significant wave height (ft)QC rejectedQC rejectedQC rejected44445588QC rejected
Mean maximum wave height (ft)152113667788131317
Mean peak period (s)121311101098810101211
Mean average period (s)101199887798109
Mean period Tm02 (s)787766667677
Mean peak wave directionWconcentration 97%Wconcentration 98%WNWconcentration 79%Wconcentration 85%Wconcentration 83%Wconcentration 95%Wconcentration 98%Wconcentration 96%WNWconcentration 95%Wconcentration 87%Wconcentration 98%Wconcentration 94%
Mean directional spread (°)27.025.026.329.028.128.726.728.425.628.226.827.8
Mean water temperature(°C)------------

Swipe sideways to see more months.

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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