Cottosloe - surf spot statistics

Best Surf Season (May - August)

The heart of the Southern Hemisphere winter locks in the most consistent and powerful surf for Cottosloe. During these months, the Indian Ocean roars to life with a steady stream of extratropical storms tracking across the Great Australian Bight, firing long-period groundswells from the WSW to WNW directions that wrap beautifully into this west-facing beach. Average wave heights peak at 2.5-2.7m with periods frequently reaching 13+ seconds, delivering powerful, lined-up sets that will have you reaching for your step-up. The wind regime also becomes more favorable as high-pressure systems settle to the south, pumping offshore E to SE breezes that groom the waves to perfection. While afternoon seabreezes can still stir things up, the early mornings are pure gold. This is the prime window for Cottosloe's best waves.

Fair Surf Season (April, September, October)

The shoulder months offer a healthy mix of swell and wind conditions, making them a reliable bet for quality sessions. April kicks off with increasing swell energy as the transition into winter begins, while September and October still hold decent winter leftovers. Average wave heights range from 2.0m to 2.6m with periods around 12-13 seconds, providing plenty of power. The main challenge is the wind: offshore flows become a little less frequent (30-43% ideal), but the windows of clean conditions are often extended when high pressure parks itself nicely over the continent. These months are ideal for those who want solid waves without the winter crowds.

Low Surf Season (November - March)

The summer and early autumn months see a distinct drop in both swell size and consistency. The storm tracks retreat poleward and the Indian Ocean goes quiet for extended periods. Average wave heights hover around 1.8-2.0m with shorter periods (11-12 seconds), translating into smaller, more inconsistent surf. Even more limiting is the wind: ideal offshore conditions occur only 25-35% of the time, as a persistent sea-breeze cycle or passing troughs bring in undesirable onshore W to NW winds that mess up the lineup. That said, if a late-season Tasman Sea low or a distant Southern Ocean storm aligns, you can still find rippable, fun-sized waves. But consistency is not your friend during these months.

August: Continued Winter Strength

August holds firm with an average wave height of 2.7m and period of 13.1s – the longest period of the year. The SW (31.9%) and WSW (14.2%) directions again provide the core swell, with W (2.9%) adding to the mix. The size distribution shows a strong peak in the 1.5-2.5m range, with 16.5% falling in the 2-2.5m band and 12.3% in 1.5-2m. Wind conditions are ideal 38% of the time, a minor decrease from July. The offshore flow is still present: E (7.5%), ENE (7.3%), ESE (6.6%) but the westerly wind component increases slightly (W 7.3%, WNW 7.4%, NW 7.0%) meaning onshore days are more common. Late winter still delivers epic power and consistency, but you’ll need to pick your windows carefully.