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Sevenstones wave buoy daily means for Jun 2011

Daily means from the Sevenstones wave buoy for Jun 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

718 wave-buoy observations covered all 30 days. Typical wave height was 3.9 ft (10th–90th percentile 2–8.5 ft), while the reported wave period averaged 7.7 seconds (10th–90th percentile 6–9 seconds). Typical wind was 19.7 mph (10th–90th percentile 10.3–28.9 mph) and mean water temperature was 13.9°C (10th–90th percentile 13.1–14.6°C). 2 of 3,563 checked values (0.1%) were excluded by quality control. Across 1 comparable year, mean wave height was above the same-month mean of 4 ft and mean wave period was below the same-month mean of 8 seconds.

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

Typical Significant Wave Height

3.9ft
Mean: 4.5 ft
P10–P90: 2 — 8.5 ft
Recorded extremes

0.3 — 11.8 ft

Available for 693 of 718 hourly samples

Mean Observed Wave Period

7.7secs
P10–P90: 6 — 9secs
Recorded extremes

3 — 26secs

Typical Observed Wind

W, 19.7mph
Mean: 19.6 mph
P10–P90: 10.3 — 28.9 mph
Recorded extremes

2.2 — 41.4 mph

Circular concentration: 43%

Mean Water Temperature

13.9°C
P10–P90: 13.1 — 14.6°C
Recorded extremes

12.6 — 16.7°C

Available for 717 of 718 hourly samples

Compared With Previous Junes

Historical baseline from 697 observations across 1 year.

Wave Height
4.5ft
0.5ft above mean
Historical mean 4ft
Wave Period
7.7s
0.3s below mean
Historical mean 8s
Water Temperature
13.9°C
Not enough comparable data

Chart showing grouped wave observations for Sevenstones. 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 Sevenstones wave buoy

Sevenstones Lightship (WMO 62107) is a UK Met Office station west of Land's End, near the Seven Stones reef in the Western Approaches. Its exposed offshore position shows Atlantic systems before they reach Cornwall and the western English Channel and provides context for a notoriously hazardous shipping area.

Its current data source reports wave height, wave period, wave direction, directional spread, wind conditions, sea temperature, separate swell and wind-sea components and wave spectra.

Metrics are rows; days run left to right.
Sevenstones wave buoy daily means Jun 2011Last observation shown
Metric
Mean significant wave height (ft)565433583222224999644743654433
Mean maximum wave height (ft)------------------------------
Mean maximum crest height (ft)------------------------------
Mean maximum trough height (ft)------------------------------
Mean peak period (s)------------------------------
Mean average period (s)------------------------------
Mean period Tm02 (s)------------------------------
Mean zero-crossing period (s)------------------------------
Mean maximum wave period (s)------------------------------
Mean reported period (s)899876786665122171088876866888666
Mean peak wave direction------------------------------
Mean wave direction------------------------------
Mean directional spread (°)------------------------------
Mean wind directionWSWconcentration 96%Nconcentration 67%NNEconcentration 89%NNEconcentration 98%Nconcentration 97%NWconcentration 73%WSWconcentration 99%WSWconcentration 98%WSWconcentration 99%WSWconcentration 92%SWconcentration 83%SEconcentration 94%SWconcentration 90%SSWconcentration 39%SWconcentration 92%Wconcentration 94%SSWconcentration 63%Wconcentration 98%SWconcentration 34%SSEconcentration 34%SWconcentration 96%Wconcentration 88%WNWconcentration 99%SWconcentration 76%WSWconcentration 95%SEconcentration 96%NNWconcentration 66%NNWconcentration 92%WNWconcentration 96%NNWconcentration 97%
Mean wind speed (mph)131114191617252815151123191216242832211923262322222015232015
Mean water temperature(°C)13.013.313.413.413.413.313.313.313.413.313.312.914.715.314.214.213.913.813.913.813.814.014.214.214.314.514.614.614.614.8

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 Met Office Marine observations.

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

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