Rhossili Bay - surf spot statistics

Best Surf Season (October - March)

The North Atlantic awakens in October, and by November the Gower Peninsula is firmly in the firing line. With average wave heights pushing above 1.2m and periods climbing into the 9-10 second range, these months deliver the most consistent swell of the year. The dominant westerly and south-westerly swell trains – perfectly aligned with Rhossili’s SSW exposure – produce powerful, long-period surf that can range from punchy 1-1.5m fun to pumping 2.5m+ XL beasts when deep Atlantic lows stall west of Ireland. The catch? Onshore winds from the same direction often accompany these storms, making clean conditions a gamble. However, when a high-pressure ridge sets up over Scandinavia, the offshore N-NE flow creates glassy, lined-up waves that make the long walk to the water well worth it. This is the prime window for size and power, especially December through February.

Fair Surf Season (April, September)

The transitional months of April and September offer a more mixed bag. Average swell heights drop to 0.9m and periods shorten to the 8-9 second range, but there’s still enough energy from the SW-W swell window to produce rideable waves for the majority of days. The ideal wind frequency holds at a moderate 7-11%, and with weaker wind speeds overall, windows of cleaner conditions can align with small to moderate swell. April sees the last of the winter swell while September hints at the coming autumn ramp-up. These are great months for loggers, mid-lengths, and anyone who prefers a more manageable, less crowded lineup – just keep an eye on those pesky onshore troughs.

Low Surf Season (May - August)

Summer brings the Gower’s infamous ‘flat spell’. From May through August, average swell heights languish around 0.7-0.8m with periods rarely exceeding 8 seconds. The dominant swell direction remains WSW-W, but the energy is minimal and often overpowered by thermal-driven onshore breezes. Ideal offshore wind frequency drops to a paltry 6-8%, meaning most days are plagued by bumpy, messy conditions. While the occasional rogue south-westerly groundswell can sneak in, the lack of consistent North Atlantic storm activity and the prevalence of high pressure over the UK make this the quietest period. For the dedicated surfer, a foam board or a summer trip to the South Atlantic is a better bet. Still, Rhossili’s beauty and the occasional small grovel session on a glassy dawn can provide a few moments of joy.

December: Winter’s Powerhouse

December rounds out the year with an average swell of 1.5m and a period of 10.0s – prime winter conditions. The dominant swell directions are WSW (36.3%) and W (17.6%), with a healthy dose of SW (8.2%) and S-SSW. This month sees the highest proportion of waves over 2.5m (0.5% from WSW alone), so expect XL days when a deep low anchors west of the UK. The ideal wind frequency is 7%, similar to November, but the wind speeds tend to be stronger. The main challenge remains the persistent onshore SW-WSW flow that accompanies the storm fronts. Yet, between lows, the post-frontal offshore N to NE winds can produce absolutely pristine conditions. December is a high-risk, high-reward month – you might get skunked by dirty wind, or you might score the best surf of the year.