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K4 wave buoy daily means for Sep 2011

Daily means from the K4 wave buoy for Sep 2011, 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

720 wave-buoy observations covered all 30 days. Typical wave height was 10.5 ft (10th–90th percentile 7.2–17.1 ft), while mean reported wave period; measurement type unavailable was 7.3 seconds (10th–90th percentile 6–9 seconds). Typical wind was 20.7 mph (10th–90th percentile 11.5–31.1 mph) and mean water temperature was 13.5°C (10th–90th percentile 12.9–14.1°C). 2 of 3,600 checked values (0.1%) were excluded by quality control. Across 1 comparable year, mean wave height was above the same-month mean of 9.2 ft and mean wave period was above the same-month mean of 7.2 seconds.

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

Typical Wave Height

10.5ft
Mean: 11.4 ft
P10–P90: 7.2 — 17.1 ft
Recorded extremes

3.9 — 25.3 ft

Available for 718 of 720 hourly samples

Mean Wave Period

7.3secs
P10–P90: 6 — 9secs
Recorded extremes

5 — 10secs

Mean Water Temperature

13.5°C
P10–P90: 12.9 — 14.1°C
Recorded extremes

12.5 — 14.3°C

Typical Wind

SW, 20.7mph
Mean: 21 mph
P10–P90: 11.5 — 31.1 mph
Recorded extremes

2.3 — 42.6 mph

Circular concentration: 61%

Compared With Previous Septembers

Historical baseline from 717 observations across 1 year.

Wave Height
11.4ft
2.2ft above mean
Historical mean 9.2ft
Wave Period
7.3s
0.1s above mean
Historical mean 7.2s
Water Temperature
13.5°C
Not enough comparable data

Chart showing grouped wave observations for K4. 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 K4 wave buoy

K4 (WMO 62105) is a UK Met Office buoy in the North Atlantic northwest of Ireland. Its remote position samples weather and sea conditions moving towards northern UK and Irish waters. The international station feed can include wind, pressure, temperature and wave observations, although the reported parameters vary with sensor availability.

Metrics are rows; days run left to right.
K4 wave buoy daily means Sep 2011Last observation shown
Metric
Mean wave height (ft)611988QC rejectedQC rejected881314182011891010916181211139810141111
Mean observed period(s)6Reported7Reported7Reported7Reported7Reported8Reported7Reported7Reported7Reported7Reported8Reported9Reported9Reported8Reported7Reported7Reported7Reported7Reported7Reported9Reported9Reported8Reported7Reported7Reported7Reported6Reported6Reported7Reported8Reported8Reported
Mean wave power(kW/m)------------------------------
Mean wind directionSconcentration 94%SWconcentration 98%WSWconcentration 98%Variableconcentration 28%SWconcentration 71%Wconcentration 98%Wconcentration 99%WSWconcentration 68%SEconcentration 73%SSEconcentration 95%SWconcentration 82%WSWconcentration 70%Wconcentration 99%Wconcentration 76%SEconcentration 96%Sconcentration 47%WNWconcentration 95%WNWconcentration 61%WSWconcentration 94%WSWconcentration 98%WSWconcentration 95%WSWconcentration 86%SSWconcentration 97%SWconcentration 96%SSWconcentration 77%SSWconcentration 89%Sconcentration 98%Sconcentration 98%Sconcentration 39%SSWconcentration 86%
Mean wind speed (mph)202117131928231319252128331120152317202630202623151725291418
Mean water temperature(°C)14.114.214.314.214.114.013.913.813.713.413.413.613.513.513.513.213.413.413.513.213.212.912.812.812.913.013.013.013.013.1

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.

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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