Carrownisky - surf spot statistics

Best Surf Season (October - March)

The North Atlantic roars to life during these months, delivering consistent, powerful swell to Carrownisky's west-facing beach. Average wave heights range from 1.5m in October to a peak of 2.1m in January, with periods often exceeding 12 seconds. This is prime time for juicy, long-period groundswell generated by a parade of extratropical cyclones tracking across the Atlantic. The dominant swell directions — WSW, W, and WNW — align perfectly with the beach's exposure, producing heavy, rippable waves in the 1.5-2.5m range. However, the trade-off is that onshore winds from the same quadrant (SW-W) frequently accompany the storms, creating choppy, blown-out conditions. The ideal offshore wind from the east (NE, ENE, E, ESE) is relatively scarce at 14-17% frequency, so you have to pick your windows carefully. When a high-pressure system settles over Scandinavia or the UK, it can deliver crisp, offshore easterlies that groom the swell into clean, powerful lines. These are the magic days when Carrownisky truly fires.

Fair Surf Season (April - September)

As the North Atlantic storm track weakens in spring and summer, Carrownisky sees a significant drop in both swell height and period. Average heights fall from 1.3m in April to a summer low of 0.9m in July, with periods averaging between 8 and 10.6 seconds. The wave quality shifts towards smaller, punchier surf that still offers fun, rippable waves on a good day. While the swell is less powerful, the wind patterns become more favorable: the frequency of ideal offshore easterlies increases to 22-23% in April and May, and remains moderate through summer (13-17%). This means more clean, glassy sessions with light winds. The dominant swell directions remain in the west-northwest quadrant, but a higher proportion of smaller, shorter-period swell (0.5-1.5m) comes from NNW to NW, which can wrap in but lacks the punch of winter groundswell. Summer also brings the occasional small, fun southwesterly swell. Overall, these months offer good opportunities for groveling on longboards or fish, especially during easterly wind events. It's a fair season that rewards patience and flexibility.

Low Surf Season (July - August)

The heart of summer brings the smallest and weakest swell of the year. Average heights bottom out at 0.9m in July and 1.0m in August, with periods around 8 seconds — at the lower end of the rideable spectrum. Most waves fall in the 0.5-1m range, often from the NW-WNW directions, leading to a lot of smaller, mushy inside waves. Onshore westerly winds dominate (13-14% offshore), so conditions can be messy and choppy unless a lucky easterly breeze lines up. This is the low season for serious surfing; expect micro-swell that needs a longboard or a groveler to get any juice. However, the beach can still offer the occasional playful wave when a summer low pressure sends in a pulse of longer-period swell. The wind statistics show a high frequency of light winds (0-10 kph) from variable directions, so dawn patrols with clean lines are possible but rare. For most surfers, this is a time to enjoy the beach and save energy for the autumn ramp-up.

September: The Autumn Awakening Begins

September marks the start of the autumnal ramp-up, with average swell height increasing to 1.2m and period to 9.9s. The swell directions are a mix: W (25.3%), WNW (20.6%), and increasing amounts from WSW (14.7%) and SW (7.9%). Wave heights spread more into the 1-1.5m and 1.5-2m categories, offering more powerful options. The ideal wind frequency is 17%, with occasional easterly winds that create clean conditions. The North Atlantic begins to stir as the first autumn lows deepen, sending pulses of longer-period swell. The water is still warm from summer, making it a pleasant month to surf. Look for combinations of building swell and high pressure over the UK that bring offshore east winds. Expect building size as the month progresses, with some days reaching the pumping range.