Porth Neigwl • Surf Spot Statistics

Best Surf Season (October - March)

This is when Porth Neigwl, also known as Hell's Mouth, earns its reputation. As the North Atlantic storm track surges southward, the UK gets hit by a relentless procession of deep low-pressure systems, and this west-northwest-facing stretch of the Llyn Peninsula opens its arms to the energy. Average swell heights climb from around 6ft (1.9m) in October to a midwinter peak of 8ft (2.5m) in December and January, with periods holding in the powerful 10-12s range. The dominant swell directions - WSW, W and WNW - are exactly what this exposed beach wants, so wave quality becomes all about the wind. These same storms often drag onshore SW/W winds, and offshore E/SE flow, from ENE through SE, remains a rare commodity, which is why the ideal wind percentage sits in the mid-to-high teens. Chase the windows behind frontal passages, when a ridge of high pressure builds in and the wind swings into the east, and you will find heavy, hollow surf.

Fair Surf Season (April, May & September)

The swell dial is turned down a few notches in the shoulder seasons, but there is still plenty of life. April averages 5ft (1.6m) at 10.1s, while May and September come in around 4-5ft (1.2-1.5m) with periods of 9-9.5s. The Atlantic still throws W/NW groundswell, but the storm windows are shorter and the gaps between swells are longer. Air and water temperatures are more forgiving, and the percentage of ideal offshore wind climbs to 21-24%, especially in April, making for cleaner, more user-friendly conditions. This is prime time for a shortboard or a fish when a decent W swell lines up.

Low Surf Season (June - August)

Summer means small, but it does not mean flat. The average swell height bottoms out at 4ft (1.2m), and the period drops to 8.2-8.7s, so most of the surf is short-period windswell generated by an active but not particularly powerful ocean. The wave rose is still dominated by W and WSW swell, which means Porth Neigwl remains exposed, but the lack of low-pressure muscle and the daily sea breezes often leave the surface lumpy. Early mornings can produce clean, rippable waves in the 2-4ft (0.6-1.2m) range, while onshore W/NW winds shut it down by afternoon. If a rare summer swell or decaying tropical storm rides through, the spot can still fire, but consistency is the trade-off.