10-day surf forecast with Strike Scores for Porthleven Reef, South Cornwall, UK
Porthleven is Cornwall's heavy-water arena--a powerful reef break that detonates beside the harbour wall when sizeable SW groundswells wrap into Mount's Bay. The wave is an A-frame but the right is the prize.
Best day in the forecast: 2026-08-06 with a score of 35/100 (Poor)
Poor conditions overall: Average score 10/100. Look for spots with better forecasts.
Moderate alignment: Swell from 247° is 22° off optimal 225°, workable but not ideal.
Too small: 1.1m is below minimum 1.2m. Waves will be weak/mushy.
Moderate period: 11s meets minimum 10s but below ideal 14s. Some groundswell energy present.
Onshore/cross-shore: 19 km/h from 292° (WNW). Destroying wave quality. Offshore range: 315°-70°.
Groundswell-dominant conditions (clean, long-period waves).
Poor conditions at Porthleven Reef. Either swell direction (247°), size (1.1m), or wind (19 km/h from 292°) is unfavorable. Consider other spots or wait for better conditions.
1.1m (3.6ft) swell from 247° (WSW) at 11.2s period
Local wind-generated waves (choppy, short-period)
Poor alignment: Swell from 272° is 47° off optimal 225°, barely within workable range 200°-260°.
Too small: 0.9m is below minimum 1.2m. Waves will be weak/mushy.
Perfect period: 14s is at or above ideal 14s. Long-period groundswell with maximum power.
Onshore/cross-shore: 13 km/h from 272° (W). Destroying wave quality. Offshore range: 315°-70°.
Poor conditions at Porthleven Reef. Either swell direction (272°), size (0.9m), or wind (13 km/h from 272°) is unfavorable. Consider other spots or wait for better conditions.
0.9m (3.0ft) swell from 272° (W) at 13.5s period
Poor alignment: Swell from 277° is 52° off optimal 225°, barely within workable range 200°-260°.
Too small: 0.4m is below minimum 1.2m. Waves will be weak/mushy.
Moderate period: 12s meets minimum 10s but below ideal 14s. Some groundswell energy present.
Onshore/cross-shore: 9 km/h from 226° (SW). Destroying wave quality. Offshore range: 315°-70°.
Poor conditions at Porthleven Reef. Either swell direction (277°), size (0.4m), or wind (9 km/h from 226°) is unfavorable. Consider other spots or wait for better conditions.
0.4m (1.3ft) swell from 277° (W) at 12.3s period
Poor alignment: Swell from 263° is 38° off optimal 225°, barely within workable range 200°-260°.
Too small: 0.3m is below minimum 1.2m. Waves will be weak/mushy.
Short period: 7s is below minimum 10s. Windswell-dominated (choppy, weak waves).
Onshore/cross-shore: 16 km/h from 133° (SE). Destroying wave quality. Offshore range: 315°-70°.
-5 points: Short-period windswell is present, creating choppy, disorganized conditions.
Poor conditions at Porthleven Reef. Either swell direction (263°), size (0.3m), or wind (16 km/h from 133°) is unfavorable. Consider other spots or wait for better conditions.
0.3m (1.0ft) swell from 263° (W) at 7s period
Moderate alignment: Swell from 237° is 12° off optimal 225°, workable but not ideal.
Too small: 0.6m is below minimum 1.2m. Waves will be weak/mushy.
Short period: 5s is below minimum 10s. Windswell-dominated (choppy, weak waves).
Moderate offshore: 14 km/h from 343° (NNW). Still grooming but noticeable wind.
-7 points: Short-period windswell is present, creating choppy, disorganized conditions.
Poor conditions at Porthleven Reef. Either swell direction (237°), size (0.6m), or wind (14 km/h from 343°) is unfavorable. Consider other spots or wait for better conditions.
0.6m (2.0ft) swell from 237° (WSW) at 5s period
Poor alignment: Swell from 267° is 42° off optimal 225°, barely within workable range 200°-260°.
Moderate offshore: 12 km/h from 333° (NNW). Still grooming but noticeable wind.
Poor conditions at Porthleven Reef. Either swell direction (267°), size (0.9m), or wind (12 km/h from 333°) is unfavorable. Consider other spots or wait for better conditions.
0.9m (3.0ft) swell from 267° (W) at 7s period
Good alignment: Swell from 228° is 3° off optimal 225°, still within prime range.
Too small: 0.5m is below minimum 1.2m. Waves will be weak/mushy.
Onshore/cross-shore: 15 km/h from 127° (SE). Destroying wave quality. Offshore range: 315°-70°.
Poor conditions at Porthleven Reef. Either swell direction (228°), size (0.5m), or wind (15 km/h from 127°) is unfavorable. Consider other spots or wait for better conditions.
0.5m (1.6ft) swell from 228° (SW) at 5s period
Poor alignment: Swell from 256° is 31° off optimal 225°, barely within workable range 200°-260°.
Marginal size: 1.3m is 1.1m from ideal 2.4m.
Short period: 8s is below minimum 10s. Windswell-dominated (choppy, weak waves).
Onshore/cross-shore: 22 km/h from 241° (WSW). Destroying wave quality. Offshore range: 315°-70°.
Poor conditions at Porthleven Reef. Either swell direction (256°), size (1.3m), or wind (22 km/h from 241°) is unfavorable. Consider other spots or wait for better conditions.
1.3m (4.3ft) swell from 256° (WSW) at 8s period
Very low confidence (8-10 day forecast, conditions may change)
Poor alignment: Swell from 257° is 32° off optimal 225°, barely within workable range 200°-260°.
Marginal size: 1.2m is 1.2m from ideal 2.4m.
Short period: 9s is below minimum 10s. Windswell-dominated (choppy, weak waves).
Onshore/cross-shore: 13 km/h from 263° (W). Destroying wave quality. Offshore range: 315°-70°.
-10 points: Previous days of onshore wind left residual chop ("morning sickness"), reducing wave quality.
Poor conditions at Porthleven Reef. Either swell direction (257°), size (1.2m), or wind (13 km/h from 263°) is unfavorable. Consider other spots or wait for better conditions.
1.2m (3.9ft) swell from 257° (WSW) at 9s period
No alignment: Swell from 0° is outside workable range 200°-260°. Wrong swell direction for this spot.
Too small: 0.0m is below minimum 1.2m. Waves will be weak/mushy.
Onshore/cross-shore: 21 km/h from 250° (WSW). Destroying wave quality. Offshore range: 315°-70°.
-7 points: Previous days of onshore wind left residual chop ("morning sickness"), reducing wave quality.
Poor conditions at Porthleven Reef. Either swell direction (0°), size (0.0m), or wind (21 km/h from 250°) is unfavorable. Consider other spots or wait for better conditions.
0.0m (0.0ft) swell from 0° (N) at 11s period
Open-Meteo Weather API (wind/weather data)