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Hornsea wave buoy daily means for Apr 2021

Daily means from the Hornsea wave buoy for Apr 2021, 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

1,436 wave-buoy observations covered all 30 days. Typical wave height was 3.1 ft (10th–90th percentile 1.3–6.1 ft), while mean average of more than one wave period type was 8.8 seconds (10th–90th percentile 4.8–12.8 seconds). Mean water temperature was 7.6°C (10th–90th percentile 6.8–8.6°C). 15 of 5,701 checked values (0.3%) were excluded by quality control. Across 11 comparable years, mean wave height was above the same-month mean of 2.7 ft and mean wave period was above the same-month mean of 7.6 seconds.

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

Typical Significant Wave Height

3.1ft
Mean: 3.6 ft
P10–P90: 1.3 — 6.1 ft
Recorded extremes

0.7 — 12.1 ft

Mean Observed Wave Period

8.8secs
P10–P90: 4.8 — 12.8secs
Recorded extremes

2.2 — 18.2secs

Available for 718 of 720 hourly samples

Observed Wave Direction

NE

Circular concentration: 91%

Mean Water Temperature

7.6°C
P10–P90: 6.8 — 8.6°C
Recorded extremes

6.7 — 9.2°C

Compared With Previous Aprils

Historical baseline from 15,648 observations across 11 years.

Wave Height
3.6ft
0.9ft above mean
Historical mean 2.69ft
Wave Period
8.8s
1.2s above mean
Historical mean 7.6s
Water Temperature
7.6°C
In line with the historical mean
Historical mean 7.6°C

Chart showing grouped wave observations for Hornsea. 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 Hornsea wave buoy

Hornsea is a Channel Coastal Observatory wave station off the rapidly eroding Holderness coast of East Yorkshire. Its North Sea record provides local wave context for Hornsea's defended frontage and the adjacent soft-cliff coastline, where storms drive substantial shoreline change.

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

Metrics are rows; days run left to right.
Hornsea wave buoy daily means Apr 2021Last observation shown
Metric
Mean significant wave height (ft)4453910953554432211113322333433
Mean maximum wave height (ft)658413151374775653222225543444654
Mean peak period (s)7689101212131312121210119810587691010854567
Mean zero-crossing period (s)445467865755764444444665443444
Mean energy period (s)------------------------------
Mean wave power, kilowatts per metre------------------------------
Mean peak wave directionNNEconcentration 100%NNEconcentration 100%NNEconcentration 99%NNEconcentration 92%NNEconcentration 96%NNEconcentration 100%NNEconcentration 100%NNEconcentration 100%NNEconcentration 100%NNEconcentration 100%NNEconcentration 100%NNEconcentration 100%NNEconcentration 100%NNEconcentration 100%NNEconcentration 99%NNEconcentration 99%NNEconcentration 97%ENEconcentration 98%NEconcentration 98%NEconcentration 98%NNEconcentration 99%NNEconcentration 100%NNEconcentration 100%NNEconcentration 100%NNEconcentration 98%ENEconcentration 61%SEconcentration 95%ENEconcentration 99%ENEconcentration 97%NEconcentration 98%
Mean directional spread (°)17.919.414.217.113.212.411.017.216.613.816.015.913.414.620.222.918.320.521.419.717.912.313.916.118.520.222.624.725.622.8
Mean water temperature(°C)7.47.47.37.37.16.96.86.86.97.06.96.97.17.27.37.57.67.87.98.18.18.48.68.58.58.68.58.48.48.4

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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 Regional Coastal Monitoring Programme.

Learn how SurfHog combines, checks and summarizes observations in the data and methodology notes.

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