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Perranporth wave buoy daily means for Sep 2020

Daily means from the Perranporth wave buoy for Sep 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

1,427 wave-buoy observations covered all 30 days. Typical wave height was 4.2 ft (10th–90th percentile 1.9–6.4 ft), while mean average of more than one wave period type was 10.3 seconds (10th–90th percentile 6.8–13.3 seconds). Mean water temperature was 16.5°C (10th–90th percentile 15.8–16.9°C). 17 of 5,659 checked values (0.3%) were excluded by quality control. Across 9 comparable years, mean wave height was below the same-month mean of 4.6 ft and mean wave period was above the same-month mean of 10 seconds.

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

Typical Significant Wave Height

4.2ft
Mean: 4.4 ft
P10–P90: 1.9 — 6.4 ft
Recorded extremes

0.9 — 16.7 ft

Mean Observed Wave Period

10.3secs
P10–P90: 6.8 — 13.3secs
Recorded extremes

4 — 22.2secs

Available for 716 of 717 hourly samples

Observed Wave Direction

W

Circular concentration: 97%

Mean Water Temperature

16.5°C
P10–P90: 15.8 — 16.9°C
Recorded extremes

15.7 — 18.2°C

Compared With Previous Septembers

Historical baseline from 6,433 observations across 9 years.

Wave Height
4.4ft
0.2ft below mean
Historical mean 4.56ft
Wave Period
10.3s
0.3s above mean
Historical mean 10s
Water Temperature
16.5°C
0.3°C above mean
Historical mean 16.2°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 Sep 2020Last observation shown
Metric
Mean significant wave height (ft)33566444434554321243225111265446
Mean maximum wave height (ft)557987576467774323643481718986710
Mean peak period (s)981011118888109111111109815171214121010101110111110
Mean zero-crossing period (s)655655555545677555657656655556
Mean energy period (s)------------------------------
Mean reported period (s)9810111189-----------------------
Mean wave power, kilowatts per metre------------------------------
Mean peak wave directionWconcentration 99%Wconcentration 99%Wconcentration 98%WNWconcentration 99%WNWconcentration 99%Wconcentration 99%Wconcentration 99%WNWconcentration 99%WNWconcentration 99%WNWconcentration 98%WNWconcentration 99%WNWconcentration 99%WNWconcentration 99%Wconcentration 99%Wconcentration 99%Wconcentration 100%Wconcentration 90%WNWconcentration 94%Wconcentration 99%Wconcentration 99%Wconcentration 94%Wconcentration 97%Wconcentration 99%Wconcentration 99%WNWconcentration 99%WNWconcentration 90%WNWconcentration 98%Wconcentration 99%Wconcentration 100%Wconcentration 99%
Mean directional spread (°)32.731.229.326.628.029.731.731.533.034.733.131.031.931.233.231.537.337.728.929.238.935.029.524.027.839.832.232.629.129.7
Mean reported wave directionWconcentration 99%Wconcentration 99%Wconcentration 99%Wconcentration 98%WNWconcentration 99%Wconcentration 99%Wconcentration 99%-----------------------
Mean water temperature(°C)16.516.516.516.516.516.616.616.716.816.716.616.716.916.816.816.816.816.716.716.917.116.816.616.316.115.915.815.815.915.8

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 Regional Coastal Monitoring Programme.

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

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