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.

December: Summer Lull Begins

December marks the start of the summer lull. Average swell height is 1.9m with an 11.7s period, and the dominant swell comes from SW (48.1%) and SSW (28.8%), with WSW at just 5.0%. The wind is ideal 25% of the time, matching November for the low point. The wind roses show strong SSW (25.4%) and S (14.3%) winds, along with a notable SW (10.8%) component – all onshore or cross-onshore for this west-facing spot. Offshore flows (E, ESE, SE) make up only about 26% of conditions, often light. The result is a lot of choppy, weak surf with limited clean windows. Early mornings with a brief E breeze can ride small grovelers, but overall, December is best saved for a different activity unless a cyclonic swell or unusual pattern delivers a surprise.