St Mary's Sound wave buoy daily means for Jul 2020

Daily means from the St Mary's Sound wave buoy for Jul 2020, including available wave height, period, direction, wind and sea temperature data.

Last observation shown Fri, Jul 31, 2020, 23:30

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

Monthly means for 2020

Period Summary

Hog Says

1,488 wave-buoy observations covered all 31 days. Typical wave height was 2.1 ft (10th–90th percentile 1–4 ft), while mean average of more than one wave period type was 7.5 seconds (10th–90th percentile 5–10.3 seconds). Mean water temperature was 14.5°C (10th–90th percentile 13.8–15.3°C). 20 of 5,913 checked values (0.3%) were excluded by quality control. Across 4 comparable years, mean wave height was above the same-month mean of 2.3 ft and mean wave period was below the same-month mean of 7.9 seconds.

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

Typical Significant Wave Height

2.1ft

Mean: 2.4 ft

P10–P90: 1 — 4 ft

Recorded extremes

0.6 — 9.1 ft

Mean Observed Wave Period

7.5secs

P10–P90: 5 — 10.3secs

Recorded extremes

3.3 — 18.2secs

Available for 741 of 744 hourly samples

Observed Wave Direction

WSW

Circular concentration: 55%

Mean Water Temperature

14.5°C

P10–P90: 13.8 — 15.3°C

Recorded extremes

13.4 — 16.8°C

Compared With Previous Julys

Historical baseline from 2,909 observations across 4 years.

Wave Height: 2.4ft; 0.1ft above mean; Historical mean 2.297ft
Wave Period: 7.5s; 0.4s below mean; Historical mean 7.9s
Water Temperature: 14.5°C; 0.8°C below mean; Historical mean 15.3°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 Jul 2020Last observation shown Jul 2020
Metric	Jul 1	Jul 2	Jul 3	Jul 4	Jul 5	Jul 6	Jul 7	Jul 8	Jul 9	Jul 10	Jul 11	Jul 12	Jul 13	Jul 14	Jul 15	Jul 16	Jul 17	Jul 18	Jul 19	Jul 20	Jul 21	Jul 22	Jul 23	Jul 24	Jul 25	Jul 26	Jul 27	Jul 28	Jul 29	Jul 30	Jul 31
Mean significant wave height (ft)	3	3	4	5	4	3	2	3	3	2	1	1	1	2	2	2	1	2	2	2	1	1	2	2	3	3	QC rejected	3	2	3	3
Mean maximum wave height (ft)	4	4	7	8	7	5	4	4	5	3	2	1	2	2	3	2	2	3	2	3	2	1	2	3	4	5	10	5	3	4	5
Mean peak period (s)	6	7	6	7	8	9	10	7	6	8	10	9	7	7	7	7	8	8	6	5	6	9	11	13	6	6	7	8	7	6	8
Mean zero-crossing period (s)	4	5	4	5	5	5	5	4	4	5	5	4	4	4	4	4	4	4	4	4	4	4	4	4	4	4	5	5	5	4	5
Mean energy period (s)	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-
Mean reported period (s)	6	7	6	7	8	9	10	7	6	8	10	9	7	7	7	7	8	8	6	6	7	10	12	12	6	6	7	8	7	6	9
Mean wave power, kilowatts per metre	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-
Mean peak wave direction	SWconcentration 98%	Wconcentration 83%	WSWconcentration 91%	SWconcentration 97%	WSWconcentration 85%	WNWconcentration 72%	Wconcentration 55%	WNWconcentration 83%	WSWconcentration 79%	NWconcentration 68%	WSWconcentration 76%	SWconcentration 92%	Wconcentration 89%	WNWconcentration 94%	NWconcentration 98%	NWconcentration 93%	NWconcentration 94%	NWconcentration 92%	NNWconcentration 58%	Econcentration 94%	SEconcentration 60%	ESEconcentration 67%	WSWconcentration 76%	SSWconcentration 89%	SWconcentration 89%	WSWconcentration 83%	SWconcentration 95%	WSWconcentration 96%	WSWconcentration 95%	Variableconcentration 30%	Wconcentration 41%
Mean directional spread (°)	40.6	47.2	39.1	40.3	49.3	56.5	57.9	48.9	43.6	54.4	58.8	55.8	48.6	45.8	41.7	48.1	53.5	53.3	52.3	33.4	44.9	53.4	43.2	40.6	41.6	45.1	33.8	50.3	49.2	43.0	45.5
Mean reported wave direction	SWconcentration 93%	Wconcentration 76%	WSWconcentration 90%	SWconcentration 95%	WSWconcentration 80%	NWconcentration 69%	Wconcentration 46%	WNWconcentration 75%	WSWconcentration 81%	NWconcentration 64%	WSWconcentration 71%	SWconcentration 77%	Wconcentration 85%	WNWconcentration 93%	NWconcentration 96%	WNWconcentration 91%	NWconcentration 92%	NWconcentration 87%	NNWconcentration 62%	Econcentration 91%	SEconcentration 56%	SSEconcentration 39%	SWconcentration 63%	SSWconcentration 89%	SWconcentration 91%	WSWconcentration 80%	SWconcentration 95%	WSWconcentration 93%	WSWconcentration 92%	Sconcentration 39%	WSWconcentration 44%
Mean water temperature(°C)	13.8	13.9	14.0	13.7	13.7	13.9	13.9	13.9	13.9	14.3	14.7	14.8	14.3	14.7	14.9	14.9	14.8	14.9	15.3	15.0	14.9	14.9	14.6	14.4	14.4	14.6	14.4	14.7	15.1	14.9	15.1

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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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