St Ives - surf spot statistics

Best Surf Season (October - March)

The North Atlantic roars to life during these months, delivering the largest and most powerful swell to St Ives. Average wave heights climb above 2m and periods consistently exceed 10s, with many pulses in the 12-14s range – true groundswell generated by deep extratropical storms tracking across the ocean. The beach faces NNW, so the optimal swell from N, WNW, NW and NNW hits the coast with authority, especially when the fetch aligns. However, this is also the stormiest time of year: prevailing winds from the SW through NW dominate, often blowing directly onshore and ruining the quality. The ideal offshore sector (S, SSW, SW, WSW) is only present about 16-20% of the time. Still, when a strong high pressure ridges into the Bay of Biscay or southern England, it pulls a crisp offshore breeze over St Ives Bay, turning the raw Atlantic energy into clean, hollow, rippable waves – the kind that make this season legendary. The NAO index plays a key role: a negative phase tends to steer low-pressure systems further south, giving the region more settled windows.

Fair Surf Season (April - May & September)

Spring and early autumn bring a noticeable transition. Swell heights drop from the winter peak but remain fun-sized – averaging 1.4 to 1.6m in April/May, and around 1.4m again in September after a summer lull. Periods settle into the 9-10s range, offering punchy, rideable waves that hold their shape better on favourable tides. The percentage of ideal offshore wind improves slightly (up to 21-22% in April and September) as high pressure systems become more common. Swell direction shifts slightly more towards the west, but there are still enough N to NW pulses to light up the sandbars. These months are a gamble: you can score a clean, glassy 3-4ft day with offshore winds, or you can face small, weak, onshore slop. It’s a transition period – less consistent than winter, but with better odds of enjoyable sessions without the gale-force winds.

Low Surf Season (June - August)

Summer is the quietest time for St Ives. The North Atlantic storm track shifts north, leaving the region under a ridge of high pressure or weak low-pressure systems. Average wave heights hover around 1.2m and periods drop to 8-8.5s – mostly short-period windswell generated by local sea breezes or distant northern lows. The dominant swell direction remains west, which is not ideal for this NNW exposure, resulting in weak, closeout conditions even when waves do arrive. The percentage of offshore wind drops back to 17-18%, but even when the breeze is from the south, the lack of swell energy means small, grovelly waves at best. Occasional mid-period pulses from decaying tropical systems can offer a brief upgrade, but they are rare. If you’re desperate for a surf, dawn patrols with a westerly swell and a light southerly wind might produce some waist-high peaks. Generally, June through August is a time for other water activities – the surf is best left to the sandbar reflections and the hope of an early autumn cold front.

September: The Resurgence

September is a breakout month as summer transitions to autumn. The average swell jumps to 1.4m and the period lengthens to 9.5s, signalling the return of groundswell energy. Swell direction favours W (28.4%) but there is a solid WNW (14.7%) and NW (5.2%) component. The wind data shows an improvement in the offshore sector: the ideal wind frequency reaches 22% – the highest of the year. This is due to more frequent high-pressure ridges from the south, bringing light southerly or southeasterly winds. September often produces classic sessions with shoulder-to-head-high waves that are clean and punchy. The crowds are also thinner as summer tourists fade. This is the month to start watching the charts again – long-period WNW swells from early autumn storms combined with a gentle offshore breeze create some of the most enjoyable and consistent surfing of the year.