Gunnamatta - surf spot statistics

Best Surf Season (March - May)

Autumn steals the show at Gunnamatta. As the Southern Ocean begins to settle after the volatile winter, the frequency of high-pressure systems tracking across the Great Australian Bight increases. These systems are the catalyst for our best conditions: they generate long-period SW groundswells that slam into the SW-facing coastline with raw power, while simultaneously providing a stable easterly flow off the land. During these months, the average swell height sits around 1.4-1.5m with periods often pushing into the 12-second range, translating to powerful, rippable walls. More importantly, the ideal wind frequency peaks at 19-22%, meaning you can count on clean, offshore breezes from the NNE through E quadrant to groom the faces into perfection. This is the sweet spot – consistent swell, favourable winds, and comfortable air temperatures.

Fair Surf Season (September - November)

Spring marks a transitional period. The Roaring Forties are still active, firing up potent storm tracks that send powerful SW and WSW groundswells our way. Average heights climb to 1.5-1.7m with periods holding around 12-13s, offering plenty of punch. However, the wind game gets trickier. The clash between lingering winter systems and building spring highs brings more frequent onshore flows from the SW and WSW. Ideal wind days drop to 16-17%, so you'll need to pick your windows carefully. When the synoptic setup aligns – a cold front passing to the south followed by a strong high building in the Bight – you get the classic combo: clean offshore E winds and heavy, long-period lines wrapping into the beach.

Low Surf Season (December - February)

Summer at Gunnamatta is a trade-off. The swell engine slows down as the storm track retreats south, resulting in average heights dipping to 1.4m and periods settling around 11-11.5s. You'll still see plenty of SW swell, but it's often less consistent and lacks the top-end power of autumn and winter. The main issue is the wind. The persistent synoptic pattern of a trough sitting over the coast, combined with sea breezes, limits clean windows to around 14-16% of the time. Mornings offer the best chance for offshore flow from the NE before the SW seabreezes kick up by midday. While you can score fun, grovelly sessions on the smaller days, the real quality is hard to come by.

May: Power and Promise

May extends the autumn excellence. Swell averages 1.5m with a 12.6s period, and the direction starts to broaden – SW drops slightly to 44%, while WSW jumps to 18% and W to 6%. This spread is a sign of more active storm tracks, generating a mix of SW and W-NW groundswell that offers variety. The wave heights are well distributed, with a strong proportion in the 1-2m range – perfect for a step-up board. Ideal wind remains high at 21%, though you may notice a slight increase in pre-frontal northwesterly winds. The trick is to catch the post-frontal clearing: after a cold front sweeps through, a high-pressure ridge builds in, turning the wind east and refreshing the swell. That’s when Gunnamatta offers long-period, heavy barrels with offshore grooming.