Skip to content
Surfhog home
Menu

Sevenstones wave buoy daily means for Jan 2011

Daily means from the Sevenstones wave buoy for Jan 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

741 wave-buoy observations covered all 31 days. Typical wave height was 4.9 ft (10th–90th percentile 2.6–10.5 ft), while the reported wave period averaged 8.5 seconds (10th–90th percentile 6–11 seconds). Typical wind was 18.4 mph (10th–90th percentile 8.1–30 mph) and mean water temperature was 9.8°C (10th–90th percentile 9–10°C). 1 of 3,705 checked values (0%) were excluded by quality control.

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

Typical Significant Wave Height

4.9ft
Mean: 5.9 ft
P10–P90: 2.6 — 10.5 ft
Recorded extremes

1.6 — 16.4 ft

Available for 740 of 741 hourly samples

Mean Observed Wave Period

8.5secs
P10–P90: 6 — 11secs
Recorded extremes

6 — 14secs

Typical Observed Wind

Variable, 18.4mph
Mean: 18.9 mph
P10–P90: 8.1 — 30 mph
Recorded extremes

2.2 — 47.3 mph

Circular concentration: 14%

Mean Water Temperature

9.8°C
P10–P90: 9 — 10°C
Recorded extremes

8 — 10°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 2011Last observation shown
Metric
Mean significant wave height (ft)543244696888101013141064553333465434
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)1111977779888891010101199111176666788811
Mean peak wave direction-------------------------------
Mean wave direction-------------------------------
Mean directional spread (°)-------------------------------
Mean wind directionENEconcentration 93%Nconcentration 84%NNEconcentration 79%SSWconcentration 95%SWconcentration 64%ENEconcentration 93%Sconcentration 86%Wconcentration 82%WSWconcentration 92%SSWconcentration 84%Wconcentration 49%WSWconcentration 98%SWconcentration 98%SWconcentration 96%SSWconcentration 98%SSWconcentration 94%ENEconcentration 42%Nconcentration 96%Econcentration 98%Econcentration 97%ENEconcentration 93%NEconcentration 93%NEconcentration 97%NNEconcentration 96%NWconcentration 87%NNEconcentration 93%ENEconcentration 98%NEconcentration 98%NEconcentration 96%NNEconcentration 93%WNWconcentration 78%
Mean wind speed (mph)10971813212421163123292924322113141312131823192025292317128
Mean water temperature(°C)10.010.09.99.910.010.010.010.010.010.010.010.010.010.010.010.010.010.09.910.09.99.610.010.010.09.89.09.09.09.09.0

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.

› Wave Buoy List