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K5 wave buoy daily means for Apr 2021

Daily means from the K5 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

719 wave-buoy observations covered all 30 days. Typical wave height was 8.2 ft (10th–90th percentile 4.6–17.4 ft), while mean reported wave period; measurement type unavailable was 7.2 seconds (10th–90th percentile 5–9 seconds). Typical wind was 16.1 mph (10th–90th percentile 6.9–30 mph) and mean water temperature was 9.5°C (10th–90th percentile 9.2–9.9°C). 2 of 3,595 checked values (0.1%) were excluded by quality control. Across 11 comparable years, mean wave height was below the same-month mean of 10.8 ft and mean wave period was the same as the same-month mean of 7.2 seconds.

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

Typical Wave Height

8.2ft
Mean: 9.8 ft
P10–P90: 4.6 — 17.4 ft
Recorded extremes

3.6 — 24.6 ft

Available for 717 of 719 hourly samples

Mean Wave Period

7.2secs
P10–P90: 5 — 9secs
Recorded extremes

4 — 12secs

Mean Water Temperature

9.5°C
P10–P90: 9.2 — 9.9°C
Recorded extremes

9 — 10.4°C

Typical Wind

Variable, 16.1mph
Mean: 17 mph
P10–P90: 6.9 — 30 mph
Recorded extremes

2.2 — 39.1 mph

Circular concentration: 14%

Compared With Previous Aprils

Historical baseline from 7,832 observations across 11 years.

Wave Height
9.8ft
1ft below mean
Historical mean 10.8ft
Wave Period
7.2s
In line with the historical mean
Historical mean 7.2s
Water Temperature
9.5°C
0.1°C below mean
Historical mean 9.6°C

Chart showing grouped wave observations for K5. 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 K5 wave buoy

K5 (WMO 64045) is a UK Met Office buoy in the far North Atlantic west of Scotland. It provides observations from a sparsely monitored ocean area upstream of the Hebrides and northern UK waters. The international feed includes marine weather and sea-temperature observations, with wave and wind parameters present only when the relevant sensors are reporting.

Metrics are rows; days run left to right.
K5 wave buoy daily means Apr 2021Last observation shown
Metric
Mean wave height (ft)6651419191417161288751215151610964565QC rejectedQC rejected665
Mean observed period(s)7Reported7Reported5Reported7Reported9Reported11Reported10Reported8Reported9Reported9Reported8Reported7Reported8Reported7Reported6Reported8Reported8Reported9Reported8Reported7Reported7Reported6Reported7Reported7Reported7Reported6Reported6Reported5Reported5Reported6Reported
Mean wave power(kW/m)------------------------------
Mean wind directionNconcentration 86%NNWconcentration 90%Wconcentration 97%WNWconcentration 85%NNWconcentration 96%NNWconcentration 95%WSWconcentration 66%NWconcentration 76%NNWconcentration 97%Nconcentration 88%SEconcentration 40%Sconcentration 91%Wconcentration 89%SSWconcentration 93%Sconcentration 99%Sconcentration 98%Sconcentration 98%WSWconcentration 54%NNWconcentration 90%NWconcentration 89%Sconcentration 40%SSEconcentration 92%SEconcentration 92%ESEconcentration 92%SSWconcentration 90%NNWconcentration 88%NNEconcentration 97%Nconcentration 96%NEconcentration 95%NNEconcentration 96%
Mean wind speed (mph)9917322520173223131296122925271515186111213122523161712
Mean water temperature(°C)9.49.49.39.29.19.29.39.39.39.39.19.29.59.79.79.69.69.69.69.69.69.99.910.010.19.89.59.49.39.6

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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.

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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