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Noirmoutier wave buoy daily means for May 2025

Daily means from the Noirmoutier wave buoy for May 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

1,488 wave-buoy observations covered all 31 days. Typical wave height was 2.8 ft (10th–90th percentile 1.8–5 ft), while mean peak wave period was 9.4 seconds (10th–90th percentile 3.8–12.9 seconds). Typical calculated wave power was approximately 2.4 kW/m (10th–90th percentile 0.8–9.6 kW/m), derived from significant wave height and energy period. 16 of 4,464 checked values (0.4%) were excluded by quality control. Across 1 comparable year, mean wave height was below the same-month mean of 4.3 ft and mean wave period was above the same-month mean of 8.6 seconds.

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

Typical Significant Wave Height

2.8ft
Mean: 3 ft
P10–P90: 1.8 — 5 ft
Recorded extremes

0.9 — 6.8 ft

Mean Observed Wave Period

9.4secs
P10–P90: 3.8 — 12.9secs
Recorded extremes

2.5 — 18.8secs

Available for 743 of 744 hourly samples

Typical Wave Power

Approximately 2.42kW/m
Mean: 3.7kW/m
P10–P90: 0.84 — 9.6kW/m
Recorded extremes

0.22 — 18.02kW/m

Calculated from significant wave height and energy period.

Typical Observed Wind

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

Available for 0 of 744 hourly samples

Mean Water Temperature

-°C
P10–P90: - — -°C

Available for 0 of 744 hourly samples

Compared With Previous Mays

Historical baseline from 1,488 observations across 1 year.

Wave Height
3ft
1.3ft below mean
Historical mean 4.265ft
Wave Period
9.4s
0.8s above mean
Historical mean 8.6s
Water Temperature
–
Not enough comparable data

Chart showing grouped wave observations for Noirmoutier. 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 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; days run left to right.
Noirmoutier wave buoy daily means May 2025Last observation shown
Metric
Mean significant wave height (ft)3333322222354222232334325565334
Mean maximum wave height (ft)4544543324586333443456547898546
Mean peak period (s)12141110467571113121110791212101111766611121110910
Mean average period (s)81196444348987745896766556988898
Mean period Tm02 (s)5764333335665644664555445666676
Mean peak wave directionWconcentration 100%Wconcentration 100%Wconcentration 100%WNWconcentration 85%Nconcentration 99%NNWconcentration 67%NNWconcentration 67%Nconcentration 76%NNWconcentration 61%Wconcentration 100%Wconcentration 100%Wconcentration 97%WNWconcentration 100%Wconcentration 100%WNWconcentration 83%NWconcentration 58%Wconcentration 95%Wconcentration 100%Wconcentration 97%Wconcentration 100%Wconcentration 100%Wconcentration 99%Wconcentration 99%Wconcentration 99%Wconcentration 99%Wconcentration 100%Wconcentration 100%Wconcentration 100%Wconcentration 100%Wconcentration 100%Wconcentration 100%
Mean directional spread (°)24.620.523.128.523.625.626.729.228.923.822.820.822.627.028.827.123.522.025.522.422.621.822.123.322.319.619.821.022.220.520.9
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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