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Noirmoutier wave buoy observations on Mon, Jul 21, 2025

Hourly readings from the Noirmoutier wave buoy for Mon, Jul 21, 2025, including available wave height, period, direction, wind and sea temperature data.

Last observation shown

Oldest observation available

Daily means for

Latest

Period Summary

Programmatically generated summary. Hog Says

48 wave-buoy observations were recorded during the day. Typical wave height was 10.4 ft (10th–90th percentile 7.5–12.1 ft), while mean peak wave period was 10.4 seconds (10th–90th percentile 9.9–10.9 seconds). Typical calculated wave power was approximately 42.8 kW/m (10th–90th percentile 19.9–58.5 kW/m), derived from significant wave height and energy period. All 144 checked values passed quality control.

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

Line chart showing wave height, wave period and sea temperature for Noirmoutier. Use the detailed observations table below for the same data in text form.

About Noirmoutier wave buoy

Noirmoutier is a CANDHIS directional buoy west of the low-lying island on the Vendée coast, operated within France's national in-situ sea-state observatory. Its position helps distinguish offshore Atlantic forcing from the sheltering and shallow-water effects around Noirmoutier and Bourgneuf Bay.

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

Metrics are rows; hours run left to right. Times use your device time zone.
Noirmoutier wave buoy hourly observations Mon, Jul 21, 2025Last observation shown
Metric
Significant wave height (ft)13111111111111111010101010111011111112111212131212121211111010109998787778778777
Maximum wave height (ft)211516151818201716141618161515141915181917172118172116171715161615131414111113111113131311111211
Peak period (s)1010111111111111111111111111111111101010111011111010111011101010911111110101011111091010101010
Average period (s)999999999999999999999999999899998999899888888888
Mean period Tm02 (s)777777777777776777777777777777776776666666666666
Peak wave directionWSWWSWWSWWSWWSWWSWWSWWSWWSWWSWWSWWSWWSWWSWWSWWWWSWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWW
Directional spread (°)16.820.719.921.917.618.819.717.818.816.419.017.016.616.721.118.715.821.718.922.117.621.816.216.416.719.318.219.815.419.919.516.219.019.716.520.420.119.619.822.019.818.021.920.221.119.920.019.5
Water temperature(°C)------------------------------------------------

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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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