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

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

Last observation shown Sun, Dec 31, 2023, 23:00

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

Monthly means for 2023

Period Summary

Hog Says

1,486 wave-buoy observations covered all 31 days. Typical wave height was 5.2 ft (10th–90th percentile 2.9–9.4 ft), while mean average of more than one wave period type was 8.4 seconds (10th–90th percentile 5.9–10.8 seconds). Mean water temperature was 11.9°C (10th–90th percentile 11.8–12.1°C). 10 of 5,943 checked values (0.2%) were excluded by quality control. Across 7 comparable years, mean wave height was above the same-month mean of 5.5 ft and mean wave period was above the same-month mean of 7.7 seconds.

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

Typical Significant Wave Height

5.2ft

Mean: 5.8 ft

P10–P90: 2.9 — 9.4 ft

Recorded extremes

2 — 17.2 ft

Mean Observed Wave Period

8.4secs

P10–P90: 5.9 — 10.8secs

Recorded extremes

3.3 — 16.7secs

Observed Wave Direction

Circular concentration: 71%

Mean Water Temperature

11.9°C

P10–P90: 11.8 — 12.1°C

Recorded extremes

11.3 — 12.3°C

Compared With Previous Decembers

Historical baseline from 5,097 observations across 7 years.

Wave Height: 5.8ft; 0.3ft above mean; Historical mean 5.5ft
Wave Period: 8.4s; 0.7s above mean; Historical mean 7.7s
Water Temperature: 11.9°C; 0.2°C above mean; Historical mean 11.7°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 Dec 2023Last observation shown Dec 2023
Metric	Dec 1	Dec 2	Dec 3	Dec 4	Dec 5	Dec 6	Dec 7	Dec 8	Dec 9	Dec 10	Dec 11	Dec 12	Dec 13	Dec 14	Dec 15	Dec 16	Dec 17	Dec 18	Dec 19	Dec 20	Dec 21	Dec 22	Dec 23	Dec 24	Dec 25	Dec 26	Dec 27	Dec 28	Dec 29	Dec 30	Dec 31
Mean significant wave height (ft)	5	3	5	6	3	7	QC rejected	8	8	8	6	7	5	3	3	4	5	5	4	4	4	4	4	6	6	4	12	10	6	8	9
Mean maximum wave height (ft)	7	4	9	10	5	12	16	12	12	12	10	11	7	4	5	5	8	7	6	6	7	6	6	9	9	7	18	15	10	14	14
Mean peak period (s)	7	5	6	10	10	7	10	9	9	9	9	9	10	9	11	8	6	7	7	8	9	9	8	7	8	9	9	10	9	8	10
Mean zero-crossing period (s)	5	4	5	6	5	5	6	6	6	6	6	6	6	5	5	4	5	5	5	5	5	5	5	5	5	5	7	7	6	6	6
Mean energy period (s)	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-
Mean reported period (s)	5	4	5	6	5	5	6	6	6	6	6	6	6	5	5	4	5	5	5	5	5	5	5	5	5	5	7	7	6	6	6
Mean wave power, kilowatts per metre	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-
Mean peak wave direction	Econcentration 99%	SSEconcentration 77%	SSWconcentration 98%	SSWconcentration 99%	SWconcentration 99%	SSWconcentration 97%	SSWconcentration 99%	SWconcentration 97%	SSWconcentration 99%	SWconcentration 98%	SWconcentration 96%	SWconcentration 100%	SWconcentration 64%	WSWconcentration 75%	WNWconcentration 89%	SWconcentration 59%	SSWconcentration 98%	SWconcentration 93%	SWconcentration 93%	WNWconcentration 91%	NWconcentration 94%	NWconcentration 90%	Wconcentration 78%	WSWconcentration 93%	SWconcentration 90%	WSWconcentration 85%	SSWconcentration 99%	SWconcentration 99%	SWconcentration 98%	SSWconcentration 99%	SSWconcentration 98%
Mean directional spread (°)	26.7	35.5	33.0	30.5	43.4	35.5	28.1	40.5	37.7	40.3	42.7	36.6	50.8	55.7	58.1	44.5	37.0	40.1	44.4	50.0	50.0	55.1	46.3	42.6	43.1	48.9	27.5	34.0	46.4	34.6	39.7
Mean reported wave direction	Econcentration 99%	SSEconcentration 77%	SSWconcentration 98%	SSWconcentration 99%	SWconcentration 99%	SSWconcentration 97%	SSWconcentration 99%	SWconcentration 96%	SWconcentration 97%	SWconcentration 98%	SWconcentration 96%	SWconcentration 100%	SWconcentration 60%	WSWconcentration 80%	WNWconcentration 81%	SWconcentration 58%	SSWconcentration 95%	SWconcentration 93%	SWconcentration 93%	WNWconcentration 91%	NWconcentration 93%	NWconcentration 91%	Wconcentration 77%	WSWconcentration 92%	WSWconcentration 90%	WSWconcentration 83%	SSWconcentration 99%	SWconcentration 99%	SWconcentration 96%	SSWconcentration 99%	SWconcentration 95%
Mean water temperature(°C)	12.2	12.2	12.2	12.1	12.0	12.0	12.0	12.0	12.0	12.1	12.1	12.1	12.0	11.9	11.9	11.9	11.9	11.9	11.9	11.8	11.8	11.8	11.8	11.8	11.8	11.8	11.8	11.8	11.7	11.7	11.6

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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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