Annual report

UK Wave and Sea Temperature Almanac 2015

A comparison of hourly-normalized observations from UK coastal and marine wave stations. The report uses only sufficiently complete station-years for each comparison and publishes the station evidence alongside every chart.

Data snapshot updated 20 August 2026. Published 21 August 2026.

Executive summary

In Southwest England, the regional monthly mean was highest in December at 2.06 m and lowest in September at 0.73 m. Other regions follow their own seasonal pattern.
The largest accepted significant wave height was 12.5 m at Cormorant AWS in January. A sustained sequence around the peak supports it as a storm event rather than an isolated spike.
The highest monthly mean sea temperature was 18.6 °C at Pevensey Bay; the lowest was 4.1 °C at Chapel Point.
The Copernicus gridded sea-surface temperature anomaly for UK and nearby waters was -0.16 °C against the 1991–2020 monthly climatology.
Automated checks examined 1,177,475 values at wave-eligible stations and excluded 8,182, or 0.69%.

Station-years represented: 40
Wave-comparison stations: 26
Temperature stations: 21
Minimum day coverage: 95%

Regional seasonal wave patterns

Combining all UK stations would mix different wave climates and overstate regions with more buoys. Each panel therefore shows one region. A monthly value first summarizes one accepted value per station per UTC hour, then gives every eligible station in that region equal weight. The shaded band averages the station-level 10th and 90th percentiles using the same equal weighting. Every panel uses the same zero-based vertical scale, so line heights can be compared directly between regions.

Region links open the current wave-buoy map. If a historical region no longer exists, the map shows all regions.

Regional seasonal patterns are shown separately. The shaded area is the equal-weighted average of each station's monthly 10th–90th percentile range. For example, Southwest England ranged from 0.73 m in September to 2.06 m in December. All panels use the same zero-based vertical scale, so their absolute heights can be compared directly. Download chart as SVG.

View chart values for average significant wave height by month and region

Regional monthly wave-height chart values
Region	Month	Mean significant wave height	10th–90th percentile range	Stations
Southwest England	January	1.62 m	0.76–2.69 m	9
Southwest England	February	1.18 m	0.37–2.04 m	9
Southwest England	March	1.17 m	0.53–1.98 m	9
Southwest England	April	0.74 m	0.39–1.27 m	9
Southwest England	May	0.93 m	0.36–1.71 m	9
Southwest England	June	0.74 m	0.24–1.33 m	9
Southwest England	July	0.84 m	0.37–1.42 m	9
Southwest England	August	0.77 m	0.34–1.30 m	9
Southwest England	September	0.73 m	0.23–1.39 m	9
Southwest England	October	0.91 m	0.28–1.73 m	9
Southwest England	November	1.54 m	0.68–2.49 m	9
Southwest England	December	2.06 m	1.30–2.94 m	9
South Coast England	January	1.00 m	0.38–1.84 m	5
South Coast England	February	0.68 m	0.22–1.40 m	5
South Coast England	March	0.64 m	0.26–1.14 m	5
South Coast England	April	0.46 m	0.22–0.86 m	5
South Coast England	May	0.70 m	0.22–1.22 m	5
South Coast England	June	0.50 m	0.24–0.88 m	5
South Coast England	July	0.60 m	0.26–0.98 m	5
South Coast England	August	0.52 m	0.22–0.92 m	5
South Coast England	September	0.56 m	0.22–1.10 m	5
South Coast England	October	0.60 m	0.20–1.18 m	5
South Coast England	November	1.04 m	0.40–1.78 m	5
South Coast England	December	1.52 m	0.92–2.22 m	5
Southeast England	January	1.20 m	0.40–2.25 m	2
Southeast England	February	0.75 m	0.20–1.70 m	2
Southeast England	March	0.75 m	0.30–1.50 m	2
Southeast England	April	0.55 m	0.20–0.95 m	2
Southeast England	May	0.75 m	0.30–1.45 m	2
Southeast England	June	0.60 m	0.20–1.00 m	2
Southeast England	July	0.70 m	0.30–1.40 m	2
Southeast England	August	0.55 m	0.20–1.05 m	2
Southeast England	September	0.65 m	0.25–1.15 m	2
Southeast England	October	0.60 m	0.25–1.05 m	2
Southeast England	November	1.25 m	0.40–2.25 m	2
Southeast England	December	1.60 m	0.90–2.35 m	2
Lincolnshire and East Anglia	January	0.75 m	0.45–1.20 m	2
Lincolnshire and East Anglia	February	0.85 m	0.35–1.45 m	2
Lincolnshire and East Anglia	March	0.75 m	0.30–1.30 m	2
Lincolnshire and East Anglia	April	0.55 m	0.20–1.05 m	2
Lincolnshire and East Anglia	May	0.60 m	0.35–0.95 m	2
Lincolnshire and East Anglia	June	0.60 m	0.30–1.00 m	2
Lincolnshire and East Anglia	July	0.60 m	0.25–1.10 m	2
Lincolnshire and East Anglia	August	0.55 m	0.20–1.00 m	2
Lincolnshire and East Anglia	September	0.80 m	0.30–1.40 m	2
Lincolnshire and East Anglia	October	0.75 m	0.35–1.40 m	2
Lincolnshire and East Anglia	November	0.70 m	0.25–1.30 m	2
Lincolnshire and East Anglia	December	0.70 m	0.40–1.05 m	2
Northeast England	January	0.85 m	0.45–1.45 m	2
Northeast England	February	1.00 m	0.40–1.80 m	2
Northeast England	March	0.85 m	0.35–1.50 m	2
Northeast England	April	0.60 m	0.30–1.15 m	2
Northeast England	May	0.70 m	0.25–1.20 m	2
Northeast England	June	0.60 m	0.30–1.00 m	2
Northeast England	July	0.80 m	0.20–1.55 m	2
Northeast England	August	0.65 m	0.25–1.15 m	2
Northeast England	September	0.90 m	0.25–1.90 m	2
Northeast England	October	0.95 m	0.30–1.55 m	2
Northeast England	November	0.75 m	0.35–1.15 m	2
Northeast England	December	1.00 m	0.55–1.65 m	2
English Channel	January	1.55 m	0.65–2.80 m	2
English Channel	February	1.20 m	0.35–2.15 m	2
English Channel	March	1.30 m	0.45–2.25 m	2
English Channel	April	0.75 m	0.35–1.30 m	2
English Channel	May	0.80 m	0.30–1.65 m	2
English Channel	June	0.70 m	0.25–1.40 m	2
English Channel	July	0.75 m	0.30–1.45 m	2
English Channel	August	0.65 m	0.25–1.20 m	2
English Channel	September	0.80 m	0.25–1.40 m	2
English Channel	October	0.80 m	0.30–1.50 m	2
English Channel	November	1.55 m	0.50–2.80 m	2
English Channel	December	1.90 m	1.10–2.95 m	2
Southern North Sea	January	1.40 m	0.40–2.70 m	1
Southern North Sea	February	0.90 m	0.20–1.90 m	1
Southern North Sea	March	1.10 m	0.30–2.20 m	1
Southern North Sea	April	0.60 m	0.20–1.10 m	1
Southern North Sea	May	0.70 m	0.20–1.50 m	1
Southern North Sea	June	0.60 m	0.20–1.10 m	1
Southern North Sea	July	0.60 m	0.20–1.40 m	1
Southern North Sea	August	0.50 m	0.20–1.00 m	1
Southern North Sea	September	0.70 m	0.20–1.20 m	1
Southern North Sea	October	0.60 m	0.20–1.10 m	1
Southern North Sea	November	1.50 m	0.40–2.90 m	1
Southern North Sea	December	1.60 m	0.90–2.50 m	1
Central and Northern North Sea	January	3.90 m	2.37–5.70 m	3
Central and Northern North Sea	February	3.40 m	1.93–4.97 m	3
Central and Northern North Sea	March	2.43 m	1.27–4.03 m	3
Central and Northern North Sea	April	2.10 m	0.97–3.23 m	3
Central and Northern North Sea	May	1.90 m	1.17–2.77 m	3
Central and Northern North Sea	June	1.53 m	0.80–2.43 m	3
Central and Northern North Sea	July	1.00 m	0.50–1.83 m	3
Central and Northern North Sea	August	1.03 m	0.53–1.57 m	3
Central and Northern North Sea	September	1.17 m	0.70–1.93 m	3
Central and Northern North Sea	October	1.67 m	0.63–2.97 m	3
Central and Northern North Sea	November	2.20 m	1.23–3.40 m	3
Central and Northern North Sea	December	2.73 m	1.33–4.20 m	3

Regional comparison

Each range bar shows the regional 10th–90th percentile bounds, with the annual mean marked in gold. Regions with one station describe that station alone. Offshore and nearshore regions should not be compared as equivalent measures of surf conditions.

Annual means and percentile bounds are equal-weighted across eligible stations in each region. The range is the average of the station-level annual P10 and P90 values, and the gold marker is the annual mean. Download chart as SVG.

View chart values for average significant wave height by region

Regional wave-height chart values
Region	Annual mean	10th–90th percentile range	Stations
Southwest England	1.11 m	0.35–2.17 m	9
South Coast England	0.74 m	0.23–1.51 m	5
Southeast England	0.84 m	0.26–1.74 m	2
Lincolnshire and East Anglia	0.69 m	0.29–1.19 m	2
Northeast England	0.79 m	0.30–1.48 m	2
English Channel	1.07 m	0.30–2.15 m	2
Southern North Sea	0.88 m	0.21–2.01 m	1
Central and Northern North Sea	2.06 m	0.70–4.09 m	3

Largest accepted height by region

Largest accepted significant wave height by region
Region	Station	Largest height
Southwest England	Bideford Bay	11.3 m
South Coast England	West Bay	6.2 m
Southeast England	Pevensey Bay	3.8 m
Lincolnshire and East Anglia	Happisburgh	3.8 m
Northeast England	Newbiggin	4.8 m
English Channel	Ch. Lightship	6.2 m
Southern North Sea	Greenwich	4.7 m
Central and Northern North Sea	Cormorant AWS	12.5 m

Sea temperatures

Monthly means are used for the range comparison. This reduces the influence of a single bad sensor reading while preserving the annual cycle. The chart shows the 15 eligible stations with the highest annual mean; all eligible stations remain in the supporting table.

Each teal bar spans the lowest to highest monthly mean, and the gold marker shows the annual mean. This is not a chart of raw recorded extrema. Download chart as SVG.

View chart values for monthly sea temperature range at the 15 warmest stations

Sea-temperature chart values
Station	Lowest monthly mean	Annual mean	Highest monthly mean
Ch. Lightship	9.5 °C	13.1 °C	16.0 °C
Greenwich	8.8 °C	13.1 °C	16.9 °C
Boscombe	6.7 °C	13.0 °C	18.0 °C
Perranporth	8.5 °C	12.9 °C	16.4 °C
Penzance	9.3 °C	12.9 °C	15.5 °C
West Bay	7.4 °C	12.9 °C	17.1 °C
Sandettie	7.3 °C	12.9 °C	17.4 °C
Looe Bay	8.9 °C	12.8 °C	15.9 °C
Bideford Bay	7.9 °C	12.8 °C	17.2 °C
Start Bay	8.6 °C	12.8 °C	16.3 °C
Dawlish	7.8 °C	12.8 °C	16.8 °C
Weymouth	7.7 °C	12.8 °C	17.3 °C
Pevensey Bay	6.5 °C	12.8 °C	18.6 °C
Porthleven	9.3 °C	12.7 °C	15.5 °C
Minehead	6.4 °C	12.5 °C	17.7 °C

Copernicus sea-temperature anomaly

Why does a 1 °C sea-temperature anomaly matter?

A degree can sound small because air temperature changes quickly. The ocean is different: water needs a great deal of energy to warm, and it releases that heat slowly. The IPCC estimates that ocean warming accounted for 91% of the heating of the climate system between 2006 and 2018.

One cubic metre of seawater

about 1.1 kWh per 1 °C

One square kilometre, 1 m deep

about 1.1 GWh per 1 °C

That second amount is roughly the energy used by a 1 kW household appliance running continuously for 127 years. Watts describe the rate of energy use; kilowatt-hours describe the total energy. The calculation uses seawater's approximate specific heat capacity of 4,000 joules per kilogram per degree Celsius.

Stored ocean heat expands seawater and raises sea level. A warmer starting point also makes damaging marine heatwaves more likely and can stress ecosystems and fisheries. These effects become more widespread with each additional increment of warming.

This is an illustration of scale, not an estimate of the heat in the chart area: a sea-surface anomaly does not mean the whole upper metre warmed uniformly. The report compares one year in UK and nearby waters with its 1991–2020 monthly baseline. It is not the global long-term warming threshold, and individual years also include natural variability.

This separate gridded view shows how warm or cool the wider sea surface was relative to the 1991–2020 monthly climatology. Positive values mean warmer than the baseline for that calendar month. The analysis covers valid ocean cells from 48–62°N and 12°W–4°E and does not alter the observed buoy findings above.

Annual SST anomaly: -0.16 °C
Largest warm anomaly: Nov +0.4 °C
Largest cool anomaly: Aug -0.76 °C
Gridded minus buoy median: -0.19 °C

Monthly anomalies compare 2015 with the matching 1991–2020 calendar-month mean. The annual anomaly is the mean of the 12 monthly anomalies, not a comparison with one annual threshold. Download chart as SVG.

View chart values for copernicus monthly sea-temperature anomaly

Copernicus monthly sea-temperature anomaly chart values
Month	Anomaly	2015 gridded mean	1991–2020 mean	Valid days
Jan	+0.16 °C	9.09 °C	8.93 °C	31
Feb	-0.16 °C	8.18 °C	8.34 °C	28
Mar	-0.07 °C	8.10 °C	8.17 °C	31
Apr	+0.04 °C	8.80 °C	8.76 °C	30
May	-0.44 °C	9.82 °C	10.26 °C	31
Jun	-0.75 °C	11.65 °C	12.40 °C	30
Jul	-0.59 °C	13.70 °C	14.29 °C	31
Aug	-0.76 °C	14.41 °C	15.16 °C	31
Sept	-0.37 °C	13.99 °C	14.35 °C	30
Oct	+0.16 °C	12.99 °C	12.84 °C	31
Nov	+0.45 °C	11.67 °C	11.22 °C	30
Dec	+0.43 °C	10.32 °C	9.89 °C	31

The gridded field had 100.0% daily coverage for this calculation. At 21 eligible buoy sites, 252 matched station-months had a mean absolute difference of 0.25 °C. The nearest valid ocean cells were no more than 3.0 km from a buoy.

Source: Copernicus Marine C3S reprocessed SST dataset C3S-GLO-SST-L4-REP-OBS-SST_202506, DOI 10.48670/moi-00169.

Coverage and quality control

A station needs observations on at least 95% of days and accepted measurements in at least 90% of annual hours to enter that metric's comparison. Stations below the threshold are still listed for transparency.

Day coverage counts any UTC day with an observation. Metric-hour coverage is tested separately before wave-height or temperature comparisons are made. Download chart as SVG.

View chart values for observation day coverage by station

Station coverage chart values
Day coverage band	Stations
Under 50%	8
50-79%	2
80-94%	4
95-99%	19
100%	7

Largest station-month peaks

These are the largest accepted monthly maxima among eligible stations. Repeated entries for a station reflect separate stormy months, not duplicate observations.

Largest accepted station-month significant wave heights
Month	Station	Region	Maximum
January	Cormorant AWS	Central and Northern North Sea	12.5 m
December	Cormorant AWS	Central and Northern North Sea	12.0 m
November	Bideford Bay	Southwest England	11.3 m
January	Anasuria AWS	Central and Northern North Sea	10.1 m
January	Beryl A AWS	Central and Northern North Sea	9.8 m
December	Beryl A AWS	Central and Northern North Sea	9.3 m
November	Cormorant AWS	Central and Northern North Sea	8.3 m
February	Cormorant AWS	Central and Northern North Sea	8.3 m

Supporting station table

This table contains every station-year considered. A dash means the metric was unavailable. “Included” indicates that the station met the day and metric-hour thresholds for that comparison.

All UK stations considered in the 2015 almanac
Station	Region	Day coverage	Wave status	Wave hours	Mean Hs	Median Hs	Annual Hs P10–P90	Maximum Hs	Temperature status	Annual temperature	Monthly mean range	Excluded values
Wave HubLegacy SurfHog archive	Southwest England	0.0%0 days	Below threshold	00.0%	Not available	Not available	Not available	Not available	Below threshold	Not available	Not available	00.00%
SevenstonesLegacy SurfHog archive	Southwest England	99.0%361 days	Included	7,99791.3%	2.07 m	1.71 m	0.70–3.90 m	8.0 m	Below threshold	12.2 °C	9.5 °C to 16.3 °C	3881.00%
PerranporthLegacy SurfHog archive	Southwest England	95.0%347 days	Included	8,17693.3%	1.68 m	1.46 m	0.58–3.11 m	6.5 m	Included	12.9 °C	8.5 °C to 16.4 °C	420.10%
Port IsaacSource recorded on station page	Southwest England	0.0%0 days	Below threshold	00.0%	Not available	Not available	Not available	Not available	Below threshold	Not available	Not available	00.00%
PenzanceLegacy SurfHog archive	Southwest England	97.0%353 days	Included	8,27494.5%	0.70 m	0.55 m	0.21–1.43 m	4.6 m	Included	12.9 °C	9.3 °C to 15.5 °C	2140.60%
PorthlevenLegacy SurfHog archive	Southwest England	97.0%353 days	Included	8,19393.5%	1.34 m	1.07 m	0.40–2.71 m	6.8 m	Included	12.7 °C	9.3 °C to 15.5 °C	1020.30%
Looe BayLegacy SurfHog archive	Southwest England	97.0%353 days	Included	8,34095.2%	0.94 m	0.76 m	0.30–1.95 m	5.2 m	Included	12.8 °C	8.9 °C to 15.9 °C	1820.50%
MineheadChannel Coastal Observatory, Legacy SurfHog archive	Southwest England	100.0%365 days	Included	8,65298.8%	0.58 m	0.52 m	0.18–1.10 m	2.7 m	Included	12.5 °C	6.4 °C to 17.7 °C	1520.20%
Bideford BayLegacy SurfHog archive	Southwest England	97.0%353 days	Included	8,32995.1%	1.34 m	1.07 m	0.37–2.74 m	11.3 m	Included	12.8 °C	7.9 °C to 17.2 °C	880.30%
Start BayLegacy SurfHog archive	Southwest England	96.0%351 days	Included	8,25894.3%	0.73 m	0.58 m	0.24–1.43 m	3.6 m	Included	12.8 °C	8.6 °C to 16.3 °C	1830.60%
DawlishChannel Coastal Observatory	Southwest England	100.0%365 days	Included	8,74799.9%	0.58 m	0.46 m	0.18–1.13 m	3.2 m	Included	12.8 °C	7.8 °C to 16.8 °C	2400.30%
West BayLegacy SurfHog archive	South Coast England	97.0%353 days	Included	8,33495.1%	0.94 m	0.70 m	0.27–2.07 m	6.2 m	Included	12.9 °C	7.4 °C to 17.1 °C	1570.50%
WeymouthLegacy SurfHog archive	South Coast England	95.0%346 days	Included	8,13792.9%	0.49 m	0.40 m	0.18–0.94 m	2.7 m	Included	12.8 °C	7.7 °C to 17.3 °C	1390.40%
BoscombeLegacy SurfHog archive	South Coast England	97.0%353 days	Included	8,38795.7%	0.61 m	0.49 m	0.21–1.19 m	3.1 m	Included	13.0 °C	6.7 °C to 18.0 °C	1490.40%
ChesilChannel Coastal Observatory	South Coast England	100.0%365 days	Included	8,74299.8%	1.10 m	0.82 m	0.30–2.32 m	6.2 m	Included	12.4 °C	7.6 °C to 17.0 °C	1530.20%
Sandown BayChannel Coastal Observatory	South Coast England	99.0%363 days	Included	8,69899.3%	0.55 m	0.43 m	0.18–1.04 m	2.8 m	Included	12.4 °C	6.7 °C to 18.1 °C	1100.20%
SeafordLegacy SurfHog archive	Southeast England	94.0%344 days	Below threshold	7,75388.5%	0.91 m	0.64 m	0.21–2.07 m	5.1 m	Below threshold	12.6 °C	6.5 °C to 18.3 °C	1080.30%
FolkestoneLegacy SurfHog archive	Southeast England	93.0%339 days	Below threshold	7,97791.1%	0.61 m	0.49 m	0.21–1.19 m	2.6 m	Below threshold	12.8 °C	6.3 °C to 18.1 °C	890.30%
Pevensey BayLegacy SurfHog archive	Southeast England	95.0%348 days	Included	8,24794.1%	0.85 m	0.67 m	0.27–1.71 m	3.8 m	Included	12.8 °C	6.5 °C to 18.6 °C	1060.30%
Bracklesham BayChannel Coastal Observatory	Southeast England	100.0%365 days	Included	8,75099.9%	0.82 m	0.64 m	0.24–1.77 m	3.7 m	Below threshold	13.3 °C	7.6 °C to 18.3 °C	1530.20%
Chapel PointChannel Coastal Observatory	Lincolnshire and East Anglia	100.0%365 days	Included	8,759100.0%	0.73 m	0.67 m	0.30–1.22 m	3.5 m	Included	11.3 °C	4.1 °C to 17.6 °C	2120.30%
HappisburghChannel Coastal Observatory	Lincolnshire and East Anglia	100.0%365 days	Included	8,759100.0%	0.64 m	0.52 m	0.27–1.16 m	3.8 m	Included	11.3 °C	4.2 °C to 17.9 °C	1560.20%
NewbigginLegacy SurfHog archive	Northeast England	96.0%350 days	Included	8,26894.4%	0.85 m	0.70 m	0.30–1.65 m	4.8 m	Included	9.7 °C	6.1 °C to 12.8 °C	1300.40%
ScarboroughLegacy SurfHog archive	Northeast England	73.0%265 days	Below threshold	6,22171.0%	1.04 m	0.88 m	0.40–1.83 m	8.0 m	Below threshold	10.0 °C	-5.0 °C to 13.3 °C	1270.50%
WhitbyLegacy SurfHog archive	Northeast England	76.0%278 days	Below threshold	6,53974.6%	0.91 m	0.73 m	0.34–1.74 m	9.5 m	Below threshold	9.5 °C	5.9 °C to 13.5 °C	1520.60%
HornseaChannel Coastal Observatory	Northeast England	100.0%365 days	Included	8,74699.8%	0.73 m	0.64 m	0.30–1.31 m	3.8 m	Included	10.3 °C	5.6 °C to 14.8 °C	2330.30%
Morecambe BayLegacy SurfHog archive	Northwest England	93.0%341 days	Below threshold	5,47562.5%	0.73 m	0.55 m	0.15–1.58 m	3.9 m	Below threshold	10.7 °C	5.6 °C to 16.8 °C	1100.50%
AberporthLegacy SurfHog archive	Wales	0.0%0 days	Below threshold	00.0%	Not available	Not available	Not available	Not available	Below threshold	Not available	Not available	00.00%
PembrokeLegacy SurfHog archive	Wales	0.0%0 days	Below threshold	00.0%	Not available	Not available	Not available	Not available	Below threshold	Not available	Not available	00.00%
Rhyl FlatsLegacy SurfHog archive	Wales	0.0%0 days	Below threshold	00.0%	Not available	Not available	Not available	Not available	Below threshold	Not available	Not available	00.00%
K7Legacy SurfHog archive	West Scotland	92.0%335 days	Below threshold	7,80189.1%	2.77 m	2.71 m	0.00–5.49 m	12.2 m	Below threshold	10.8 °C	9.0 °C to 12.4 °C	1,8525.40%
JerseyLegacy SurfHog archive	English Channel	0.0%0 days	Below threshold	00.0%	Not available	Not available	Not available	Not available	Below threshold	Not available	Not available	00.00%
SandettieLegacy SurfHog archive	English Channel	96.0%350 days	Included	8,29694.7%	0.67 m	0.49 m	0.21–1.40 m	3.5 m	Included	12.9 °C	7.3 °C to 17.4 °C	2880.70%
Ch. LightshipLegacy SurfHog archive	English Channel	99.0%361 days	Included	8,37295.6%	1.46 m	1.19 m	0.40–2.90 m	6.2 m	Included	13.1 °C	9.5 °C to 16.0 °C	70.00%
GreenwichLegacy SurfHog archive	Southern North Sea	99.0%361 days	Included	8,28694.6%	0.88 m	0.61 m	0.21–2.01 m	4.7 m	Included	13.1 °C	8.8 °C to 16.9 °C	1700.40%
Anasuria AWSLegacy SurfHog archive	Central and Northern North Sea	96.0%350 days	Included	8,34095.2%	1.04 m	0.00 m	0.00–2.99 m	10.1 m	Below threshold	8.4 °C	6.9 °C to 12.7 °C	4,31311.70%
Beryl A AWSLegacy SurfHog archive	Central and Northern North Sea	96.0%350 days	Included	8,31895.0%	2.41 m	2.01 m	1.01–4.39 m	9.8 m	Below threshold	Not available	Not available	910.30%
Brent "A" AWSLegacy SurfHog archive	Central and Northern North Sea	0.0%0 days	Below threshold	00.0%	Not available	Not available	Not available	Not available	Below threshold	Not available	Not available	00.00%
Cormorant AWSLegacy SurfHog archive	Central and Northern North Sea	96.0%350 days	Included	8,28294.5%	2.74 m	2.41 m	1.10–4.91 m	12.5 m	Below threshold	Not available	Not available	240.10%
Eider AWSLegacy SurfHog archive	Central and Northern North Sea	0.0%0 days	Below threshold	00.0%	Not available	Not available	Not available	Not available	Below threshold	Not available	Not available	00.00%

Method and limitations

The analysis uses the newest stored 2015 annual snapshot for each station in the defined UK coastal and marine regions. Measurements are normalized to one accepted value per station per UTC hour without filling gaps. Regional and monthly comparisons weight eligible stations equally. Temperatures in the findings are monthly means, while wave peaks are accepted individual significant wave heights.

Offshore and nearshore stations are not directly comparable as measures of surf conditions. Coverage does not guarantee sensor accuracy, and automated checks can miss sustained faults. Source availability and later corrections can change a rebuilt annual snapshot. See the full data and methodology notes for source terms, hard limits, unit conversions and the observed-versus-calculated distinction.

Copernicus anomalies are calculated independently from the buoy summaries. Daily 0.05° analysed SST is averaged across valid ocean grid cells using cosine-latitude area weights, then summarized to monthly means. Each monthly anomaly is measured against the matching 1991–2020 monthly climatology, and the annual anomaly is the mean of those 12 differences. The rectangular 48–62°N, 12°W–4°E window is a reproducible analysis area, not a legal or forecast-region boundary. Buoy comparisons use the nearest valid ocean grid cell within 20 km, so coastal position and grid-cell footprint can produce genuine differences.

Cite and share this report

Suggested citation: SurfHog (2026), “UK Wave and Sea Temperature Almanac 2015”, data updated 20 August 2026, https://www.surfhog.co.uk/reports/uk-wave-sea-temperature-almanac-2015

Cite the original observation providers as well as SurfHog when using a specific station finding. Provider and reuse details are listed in the data and methodology page.