Llangennith - surf spot statistics

Best Surf Season (October - March)

The heart of the North Atlantic storm track delivers the goods to Llangennith during autumn and winter. As the jet stream strengthens and low-pressure systems march eastwards, consistent WSW and W swells flood the Gower Peninsula. Average wave heights hover between 1.2m and 1.6m with periods regularly pushing 10s or more, bringing powerful, long-period lines that wrap into the beach. However, the key is wind – the prevailing westerlies often ruin the surface with onshore conditions. The best days come when high pressure over Scandinavia funnels crisp easterly winds (NE, ENE, E, ESE) across the Bristol Channel, grooming the swell into clean, hollow walls. Winter months see the highest swell potential, but patience is required to score the perfect window.

Fair Surf Season (April - June)

Spring sees a gradual decline in swell size as the North Atlantic calms down. Average heights drop to 0.8–0.9m and periods shorten to 8–9s, favouring fun-sized, rippable waves rather than heavy barrels. The wind patterns become more variable, with a higher frequency of offshore directions – particularly in April when ideal wind occurs 11% of the time, the highest annual figure. This can lead to clean, smooth conditions on smaller swells, offering great groveling and longboard fun. While the heavy winter sets are gone, spring offers more user-friendly surf with better odds of glassy mornings.

Low Surf Season (July - September)

Summer is the quietest period at Llangennith. Swell heights average 0.7–0.9m with periods under 8s, resulting in weak, sloppy waves – often too small to break properly. The dominant wind is firmly from the SW-W quadrant, blowing directly onshore and destroying any chance of quality. Ideal offshore wind drops to a mere 4–6% of the time, making it a rare event to find clean waves. Occasional pulses from distant storms can produce short-period SW swell, but without the right wind alignment, it’s mostly a season for swimming or sunbathing. For the dedicated surfer, dawn patrols during easterly breezes offer the only hope of a few rideable bumps.

December: Peak Winter Swell

December returns to full winter strength with an average swell height of 1.5m and period of 10.0s. The swell is powerful and consistent, sourced primarily from WSW (36%) and W (18%), with notable contributions from SW (8%) and significant wave heights above 2m. The wind remains the limiting factor: ideal offshore wind occurs only 7% of the time, and the wind rose shows a high frequency of strong SW-W winds. However, when a cold front clears and high pressure builds from the east, the combination of long-period ground swell and offshore easterlies produces some of the best waves of the year. December rewards the patient and the prepared – the North Atlantic's fury is tamed only by the perfect wind alignment.