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Perranporth wave buoy daily means for Dec 2020

Daily means from the Perranporth wave buoy for Dec 2020, 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

1,481 wave-buoy observations covered all 31 days. Typical wave height was 7.3 ft (10th–90th percentile 3.9–13.3 ft), while mean average of more than one wave period type was 10.7 seconds (10th–90th percentile 6.3–15.4 seconds). Typical wind was 0 mph and mean water temperature was 10.7°C (10th–90th percentile 10.2–11.3°C). 16 of 6,631 checked values (0.2%) were excluded by quality control. Across 10 comparable years, mean wave height was above the same-month mean of 7.3 ft and mean wave period was below the same-month mean of 11.8 seconds.

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

Typical Significant Wave Height

7.3ft
Mean: 8.1 ft
P10–P90: 3.9 — 13.3 ft
Recorded extremes

1 — 19.5 ft

Mean Observed Wave Period

10.7secs
P10–P90: 6.3 — 15.4secs
Recorded extremes

3.9 — 20secs

Observed Wave Direction

WNW

Circular concentration: 96%

Mean Water Temperature

10.7°C
P10–P90: 10.2 — 11.3°C
Recorded extremes

9.2 — 11.8°C

Compared With Previous Decembers

Historical baseline from 7,351 observations across 10 years.

Wave Height
8.1ft
0.8ft above mean
Historical mean 7.316ft
Wave Period
10.7s
1.1s below mean
Historical mean 11.8s
Water Temperature
10.7°C
0.3°C below mean
Historical mean 11°C

Chart showing grouped wave observations for Perranporth. 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 Perranporth wave buoy

Perranporth is a National Network Datawell Directional WaveRider in about 14 metres of water off Cornwall's exposed north coast. First deployed on 18 December 2006, it records Atlantic swell approaching Perranporth and neighbouring beaches; a separate shore station supplies the local weather context.

Its current data source reports wave height, wave period, wave direction, directional spread, wave power and sea temperature.

Metrics are rows; days run left to right.
Perranporth wave buoy daily means Dec 2020Last observation shown
Metric
Mean significant wave height (ft)45912124376891271198671110758104915151265
Mean maximum wave height (ft)6713181865109121317101613129101615108121561322231989
Mean peak period (s)981211991198911151315141311141714121012868-11987
Mean zero-crossing period (s)5567756556676887668766764577655
Mean energy period (s)-------------------------------
Mean reported period (s)5567756556676887668766764577755
Mean wave power, kilowatts per metre-------------------------------
Mean peak wave directionWNWconcentration 97%WNWconcentration 99%Wconcentration 98%WNWconcentration 98%NWconcentration 100%Wconcentration 99%Wconcentration 99%WNWconcentration 97%Wconcentration 95%Wconcentration 99%Wconcentration 99%WNWconcentration 99%Wconcentration 99%Wconcentration 100%Wconcentration 99%Wconcentration 98%Wconcentration 99%Wconcentration 98%WNWconcentration 100%WNWconcentration 100%Wconcentration 99%Wconcentration 100%WNWconcentration 88%NNWconcentration 100%NWconcentration 98%WNWconcentration 99%WNWconcentration 99%WNWconcentration 98%WNWconcentration 100%WNWconcentration 98%WNWconcentration 96%
Mean directional spread (°)36.537.132.530.932.931.832.534.031.528.226.423.830.223.127.929.527.629.526.426.630.626.329.238.244.630.620.922.326.933.136.6
Mean reported wave directionWNWconcentration 96%WNWconcentration 97%Wconcentration 97%WNWconcentration 97%WNWconcentration 99%Wconcentration 99%Wconcentration 99%WNWconcentration 96%Wconcentration 95%Wconcentration 99%Wconcentration 99%WNWconcentration 99%Wconcentration 98%Wconcentration 99%Wconcentration 98%Wconcentration 98%Wconcentration 98%Wconcentration 98%WNWconcentration 99%WNWconcentration 100%Wconcentration 99%Wconcentration 99%WNWconcentration 88%NWconcentration 99%NWconcentration 95%WNWconcentration 99%WNWconcentration 99%WNWconcentration 98%WNWconcentration 99%WNWconcentration 97%WNWconcentration 95%
Mean water temperature(°C)11.711.611.511.111.010.810.710.610.410.410.610.410.610.710.610.710.710.810.810.811.011.211.210.910.610.610.510.310.29.99.7

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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.

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 Regional Coastal Monitoring Programme.

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

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