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Historical surf replay

Mount's Bay surf conditions on Thu, Aug 20, 2026

Mount's Bay conditions using shared west Cornwall weather forecasts and observations, Porthleven inshore readings, and offshore signals from Sevenstones and Brittany in the Bay of Biscay. Each source keeps its own location and role so the view provides coastal context without presenting nearby buoy readings as measurements at the surf break.

Surf Day Summary

AI-generated summary. Hog Says

There were small to moderate, fairly clean waves at Porthleven: the WSW swell was well aligned, with observed inshore waves around 3.2ft and an average eight-second peak period. Cross-offshore NW winds near 11mph helped keep conditions clean, while the larger NW Brittany swell was largely sheltered.

Generated from the completed forecast and observations shown on this page.

Day at a glance

Forecast and observations in their coastal context

Observed in west Cornwall

Godrevy wind and weather

Wind speed
8–15 mph

Wind backing northerly to westerly

NW 305°cross-offshore

24 observations. Godrevy is close enough to provide useful regional wind context for both coasts, although local effects can differ. Explore all weather readings.

Atlantic and Western Approaches signal

Sevenstones

Significant wave height
5.9–7.9 ft
Average period
6.9–8.3s
Reported wave direction
Unavailable
Exposure unavailable

24 readings. steady height trend; medium confidence from metoffice. Open the Sevenstones archive.

Bay of Biscay southerly-swell signal

Brittany

Significant wave height
6.6–10.8 ft
Peak period
6.9–12.2s
Peak wave direction
NW 316°
largely sheltered from this direction

24 readings. steady height trend; high confidence from metoffice. Open the Brittany archive.

South-coast inshore response

Porthleven

Significant wave height
2.6–3.6 ft
Peak period
5.9–11.8s
Peak wave direction
WSW 246°
well aligned with this coast

48 readings. falling height trend; high confidence from cco. Open the Porthleven archive.

These sources describe different locations and exposures. Offshore and inshore buoy readings provide context for Mount's Bay; they are not measurements taken at the surf break itself. Directional labels use Porthleven as a representative south-west-facing swell window; individual peaks and beaches can differ.

Hour-by-hour replay

The charts share the same time axis so offshore signals, inshore readings and regional wind can be compared without treating them as the same measurement location.

Two line charts show wave height and wind speed through the selected day for Mount's Bay. The detailed table following the charts contains the same values in text form.

Swell and sea height through the day

Wind speed through the day

Metrics are rows; hours run left to right. Times use your device time zone.
Hourly forecast and observation values
Metric
Godrevy forecast weather (3-hourly)
Observed weather
Observed wind (mph)9W10W9W11W10W10W12W8WNW13NW12WNW11WNW12WNW15NW13NNW14NW14NW13NW13NW14NNW11NW13NNW11NNW9N9N
Sevenstones Significant wave height (ft)6.26.96.26.66.67.97.27.27.27.96.27.26.96.66.26.96.96.26.26.26.25.95.95.9
Sevenstones Observed wave period (s)6.97.17.17.47.27.58.17.27.97.97.68.07.67.37.68.28.07.57.58.17.78.37.87.6
Sevenstones Observed wave directionUnavailableUnavailableUnavailableUnavailableUnavailableUnavailableUnavailableUnavailableUnavailableUnavailableUnavailableUnavailableUnavailableUnavailableUnavailableUnavailableUnavailableUnavailableUnavailableUnavailableUnavailableUnavailableUnavailableUnavailable
Brittany Significant wave height (ft)6.67.28.58.57.510.210.29.58.59.28.910.89.58.28.59.210.59.59.29.510.27.98.98.2
Brittany Observed wave period (s)7.39.58.88.510.211.110.28.511.111.18.511.611.110.78.08.56.910.29.111.67.89.112.211.1
Brittany Observed wave directionNW 311°NW 324°NW 315°NW 306°NW 307°NW 313°NW 310°NW 319°WNW 298°NW 317°NW 321°NNW 330°NW 326°WNW 300°NW 309°NNW 330°NW 315°NW 307°WNW 303°NNW 332°NW 324°NNW 332°NW 311°NW 322°
Porthleven Significant wave height (ft)3.23.43.43.53.43.33.33.63.53.53.73.53.33.23.02.82.82.82.82.82.92.82.72.5
Porthleven Observed wave period (s)6.37.76.37.77.76.77.77.18.37.78.37.75.97.76.77.77.110.511.111.111.17.79.111.8
Porthleven Observed wave directionWSW 238°WSW 248°WSW 239°WSW 246°WSW 248°WSW 238°WSW 249°WSW 243°WSW 252°WSW 248°WSW 250°WSW 245°WSW 242°WSW 252°WSW 243°WSW 250°WSW 246°WSW 249°WSW 252°WSW 252°WSW 250°WSW 248°WSW 245°WSW 245°

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