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Chesil wave buoy daily means for May 2020

Daily means from the Chesil wave buoy for May 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

1,488 wave-buoy observations covered all 31 days. Typical wave height was 1.5 ft (10th–90th percentile 0.9–3.9 ft), while mean average of more than one wave period type was 8.5 seconds (10th–90th percentile 4.8–12.5 seconds). Mean water temperature was 12.6°C (10th–90th percentile 11.6–13.9°C). 12 of 5,873 checked values (0.2%) were excluded by quality control. Across 10 comparable years, mean wave height was below the same-month mean of 2.2 ft and mean wave period was above the same-month mean of 7.6 seconds.

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

Typical Significant Wave Height

1.5ft
Mean: 2 ft
P10–P90: 0.9 — 3.9 ft
Recorded extremes

0.5 — 7.8 ft

Mean Observed Wave Period

8.5secs
P10–P90: 4.8 — 12.5secs
Recorded extremes

1.7 — 16.7secs

Available for 743 of 744 hourly samples

Observed Wave Direction

SSW

Circular concentration: 83%

Mean Water Temperature

12.6°C
P10–P90: 11.6 — 13.9°C
Recorded extremes

11.3 — 15.8°C

Compared With Previous Mays

Historical baseline from 14,847 observations across 10 years.

Wave Height
2ft
0.2ft below mean
Historical mean 2.231ft
Wave Period
8.5s
0.9s above mean
Historical mean 7.6s
Water Temperature
12.6°C
0.9°C above mean
Historical mean 11.7°C

Chart showing grouped wave observations for Chesil. 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 Chesil wave buoy

Chesil is a Channel Coastal Observatory National Network wave station off Dorset's exposed Jurassic Coast. It records waves approaching Chesil Beach and the western side of Portland, providing a nearshore reference for the long shingle barrier and the communities and infrastructure behind it.

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.
Chesil wave buoy daily means May 2020Last observation shown
Metric
Mean significant wave height (ft)QC rejected322322211221111222115QC rejected32111111
Mean maximum wave height (ft)8544433321421222332227953222222
Mean peak period (s)87910889911991010671064791177910101389108
Mean zero-crossing period (s)5455556765655543334564545664444
Mean energy period (s)-------------------------------
Mean wave power, kilowatts per metre-------------------------------
Mean peak wave directionSWconcentration 100%SWconcentration 100%SWconcentration 100%SWconcentration 100%Sconcentration 95%SSWconcentration 93%SWconcentration 99%SWconcentration 100%SWconcentration 80%Sconcentration 51%Sconcentration 91%Sconcentration 86%SSWconcentration 77%SSEconcentration 99%Sconcentration 77%SSWconcentration 80%SWconcentration 96%SWconcentration 99%SWconcentration 99%SWconcentration 92%SWconcentration 91%SWconcentration 100%SWconcentration 100%SWconcentration 100%SWconcentration 91%SSWconcentration 76%SSWconcentration 81%Sconcentration 84%Sconcentration 86%Sconcentration 74%Sconcentration 73%
Mean directional spread (°)16.132.542.741.930.134.344.341.858.451.032.248.062.132.137.054.934.626.845.257.555.821.918.929.641.451.058.344.443.055.347.9
Mean water temperature(°C)11.611.611.711.711.711.711.912.112.312.111.812.011.811.711.912.012.212.412.713.213.412.913.513.713.914.214.013.813.814.014.0

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 Regional Coastal Monitoring Programme.

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

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