St Mary's Sound wave buoy daily means for May 2023

Daily means from the St Mary's Sound wave buoy for May 2023, including available wave height, period, direction, wind and sea temperature data.

Last observation shown Wed, May 31, 2023, 23:30

Data available: Sun, Jul 3, 2016 to Sat, Aug 22, 2026

Monthly means for 2023

Period Summary

Hog Says

1,485 wave-buoy observations covered all 31 days. Typical wave height was 2.3 ft (10th–90th percentile 1.4–4.7 ft), while mean average of more than one wave period type was 8.4 seconds (10th–90th percentile 5.5–11.5 seconds). Mean water temperature was 12.3°C (10th–90th percentile 11.3–13.7°C). 23 of 5,937 checked values (0.4%) were excluded by quality control. Across 6 comparable years, mean wave height was below the same-month mean of 3.1 ft and mean wave period was above the same-month mean of 7.4 seconds.

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

Typical Significant Wave Height

2.3ft

Mean: 2.8 ft

P10–P90: 1.4 — 4.7 ft

Recorded extremes

0.6 — 9.8 ft

Mean Observed Wave Period

8.4secs

P10–P90: 5.5 — 11.5secs

Recorded extremes

2.9 — 15.4secs

Available for 743 of 744 hourly samples

Observed Wave Direction

Variable

Circular concentration: 13%

Most common: ESE (16%) · circular mean WNW

Mean Water Temperature

12.3°C

P10–P90: 11.3 — 13.7°C

Recorded extremes

11.1 — 14.8°C

Compared With Previous Mays

Historical baseline from 4,270 observations across 6 years.

Wave Height: 2.8ft; 0.3ft below mean; Historical mean 3.1ft
Wave Period: 8.4s; 1s above mean; Historical mean 7.4s
Water Temperature: 12.3°C; 0.5°C above mean; Historical mean 11.8°C

Show 10th–90th percentile ranges

About St Mary's Sound wave buoy

St Mary's Sound station lies between St Mary's and St Agnes in the Isles of Scilly. The National Network first deployed a Datawell Directional WaveRider here in May 2014, establishing a nearshore record for an archipelago exposed to Atlantic swell and important to local navigation and coastal management.

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

St Mary's Sound wave buoy daily means May 2023Last observation shown May 2023
Metric	May 1	May 2	May 3	May 4	May 5	May 6	May 7	May 8	May 9	May 10	May 11	May 12	May 13	May 14	May 15	May 16	May 17	May 18	May 19	May 20	May 21	May 22	May 23	May 24	May 25	May 26	May 27	May 28	May 29	May 30	May 31
Mean significant wave height (ft)	2	2	6	5	4	4	3	4	3	4	3	2	2	2	2	2	1	1	2	2	2	2	3	2	2	3	3	2	4	5	4
Mean maximum wave height (ft)	3	3	10	8	6	7	5	6	5	6	5	3	3	3	4	3	2	1	2	3	3	3	4	2	3	4	5	3	7	8	6
Mean peak period (s)	9	8	6	7	7	8	8	7	8	9	11	9	10	12	8	10	9	9	11	10	10	9	8	11	10	8	6	6	6	7	6
Mean zero-crossing period (s)	6	5	5	5	5	6	5	5	5	5	5	5	5	5	4	5	4	5	5	5	5	4	4	4	4	4	4	3	4	5	4
Mean energy period (s)	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-
Mean reported period (s)	5	5	5	5	5	6	5	5	5	5	5	5	5	5	4	5	4	5	5	5	5	4	4	4	4	4	5	3	4	5	4
Mean wave power, kilowatts per metre	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-
Mean peak wave direction	WSWconcentration 94%	SWconcentration 69%	ESEconcentration 98%	SEconcentration 70%	SSWconcentration 96%	SSWconcentration 99%	SWconcentration 98%	SWconcentration 83%	WSWconcentration 79%	Wconcentration 85%	NWconcentration 94%	WNWconcentration 90%	Nconcentration 63%	NNWconcentration 91%	NNWconcentration 74%	NWconcentration 86%	Wconcentration 60%	SWconcentration 50%	NWconcentration 78%	NWconcentration 68%	WNWconcentration 70%	Nconcentration 69%	NNEconcentration 65%	NWconcentration 89%	Nconcentration 60%	ENEconcentration 41%	ESEconcentration 100%	Econcentration 77%	ESEconcentration 100%	ESEconcentration 100%	ESEconcentration 100%
Mean directional spread (°)	52.9	47.4	31.2	35.3	34.1	34.5	43.6	42.3	44.0	51.3	54.4	59.8	50.8	46.2	45.6	57.0	61.9	55.6	44.7	52.6	55.4	44.3	38.0	56.6	49.4	38.1	23.8	31.2	25.1	20.4	20.9
Mean reported wave direction	WSWconcentration 95%	SWconcentration 72%	ESEconcentration 98%	SEconcentration 69%	SSWconcentration 96%	SSWconcentration 99%	SWconcentration 98%	SWconcentration 83%	WSWconcentration 83%	Wconcentration 86%	NWconcentration 94%	WNWconcentration 85%	Nconcentration 69%	NNWconcentration 91%	NNWconcentration 79%	NWconcentration 85%	Wconcentration 53%	SSWconcentration 46%	NWconcentration 65%	NWconcentration 63%	NWconcentration 58%	Nconcentration 69%	NNEconcentration 67%	NNWconcentration 77%	Nconcentration 67%	ENEconcentration 44%	ESEconcentration 100%	ESEconcentration 84%	ESEconcentration 100%	ESEconcentration 100%	ESEconcentration 100%
Mean water temperature(°C)	11.3	11.4	11.3	11.3	11.4	11.5	11.6	11.6	11.6	11.7	11.7	11.8	12.1	12.1	12.0	12.3	12.3	12.2	12.2	12.5	12.4	12.6	12.9	12.8	13.1	13.6	13.5	13.7	14.4	13.9	13.7

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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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