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Sevenstones wave buoy daily means for Jan 2012

Daily means from the Sevenstones wave buoy for Jan 2012, 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

737 wave-buoy observations covered all 31 days. Typical wave height was 6.9 ft (10th–90th percentile 4.3–15 ft), while the reported wave period averaged 8.6 seconds (10th–90th percentile 7–10 seconds). Typical wind was 25.3 mph (10th–90th percentile 12.7–35.7 mph) and mean water temperature was 11.1°C (10th–90th percentile 10.7–11.4°C). 5 of 3,676 checked values (0.1%) were excluded by quality control. Across 1 comparable year, mean wave height was above the same-month mean of 5.9 ft and mean wave period was above the same-month mean of 8.5 seconds.

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

Typical Significant Wave Height

6.9ft
Mean: 8 ft
P10–P90: 4.3 — 15 ft
Recorded extremes

2.3 — 22 ft

Available for 734 of 737 hourly samples

Mean Observed Wave Period

8.6secs
P10–P90: 7 — 10secs
Recorded extremes

6 — 12secs

Available for 733 of 737 hourly samples

Typical Observed Wind

W, 25.3mph
Mean: 24.7 mph
P10–P90: 12.7 — 35.7 mph
Recorded extremes

4.6 — 50.6 mph

Circular concentration: 46%

Available for 734 of 737 hourly samples

Mean Water Temperature

11.1°C
P10–P90: 10.7 — 11.4°C
Recorded extremes

10.4 — 11.7°C

Available for 735 of 737 hourly samples

Compared With Previous Januarys

Historical baseline from 741 observations across 1 year.

Wave Height
8ft
2.1ft above mean
Historical mean 5.9ft
Wave Period
8.6s
0.1s above mean
Historical mean 8.5s
Water Temperature
11.1°C
1.3°C above mean
Historical mean 9.8°C

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 Jan 2012Last observation shown
Metric
Mean significant wave height (ft)10161914169776665459747999866913105356
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)9111099981099988789898888988998897
Mean peak wave direction-------------------------------
Mean wave direction-------------------------------
Mean directional spread (°)-------------------------------
Mean wind directionWSWconcentration 88%Wconcentration 91%Wconcentration 80%WNWconcentration 94%NWconcentration 89%WNWconcentration 88%NWconcentration 96%WNWconcentration 90%Wconcentration 98%WSWconcentration 90%WSWconcentration 96%WNWconcentration 92%ENEconcentration 74%SEconcentration 99%ESEconcentration 98%SEconcentration 95%Sconcentration 97%WSWconcentration 97%WNWconcentration 92%WNWconcentration 97%WNWconcentration 97%NWconcentration 95%WNWconcentration 94%Wconcentration 99%SWconcentration 89%Wconcentration 93%NWconcentration 96%Nconcentration 94%Sconcentration 45%Variableconcentration 21%ESEconcentration 95%
Mean wind speed (mph)27314135382326171813142013293319192430313426212728322517121731
Mean water temperature(°C)11.611.411.511.411.511.411.411.311.411.411.311.311.311.110.810.810.911.111.111.011.110.911.011.011.010.710.710.710.610.710.5

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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