Gunnamatta • Surf Spot Statistics

Best Surf Season (March - May)

Gunnamatta is a full-on, exposed sand-bottom beach break on the Mornington Peninsula, facing southwest directly into the Southern Ocean. When the Roaring Forties light up, this stretch of coast feels the full force of the swell. The best months are March through May. Average heights sit in the solid 4-5ft (1.2-1.5m) range, wave periods climb from 12.0s to 12.6s, and SSW, SW, WSW and W swell account for roughly 80% of all wave energy. This is also the cleanest wind window of the year: ideal N/NE/E offshore winds are present 19-22% of the time, with April peaking at 22%. The synoptic setup is classic autumn-strong Southern Ocean lows tracking below the Bight, slow-moving highs over the Tasman Sea, and NE/E offshore winds grooming the face. When the Southern Annular Mode trends negative, the mid-latitude storm track gets an extra boost and the quality ceiling goes even higher. This is the sweet spot: powerful long-period groundswell, lighter winds, and fewer summer sea breezes.

Fair Surf Season (June - November)

Winter and spring are the biggest but most unpredictable months at Gunnamatta. From June through August, average swell heights climb to 5-6.5ft (1.5-2m), and periods reach the powerful 12.4-12.9s bracket. The Southern Ocean is at full throttle, but the wind is the trade-off. Strong NNW and WNW flow becomes increasingly common, while ideal offshore wind drops to just 14-16%. Onshore and cross-shore winds can turn the heavy sandbars into closeout chaos. September and October remain active, with SW swell dominating again and some of the longest periods of the year, but the wind is still a lottery. November starts to ease back toward summer. For the dedicated surfer there are still great days, especially when a high pressure ridge parks over the Tasman Sea and delivers light E/NE winds around a strong SW groundswell.

Low Surf Season (December - February)

Summer is the low season in relative terms. The Southern Ocean still sends consistent SSW/SW energy toward Gunnamatta, but average heights ease to around 4-5ft (1.2-1.5m) and periods drop to 11.2-11.5s. The afternoon sea breeze from the S/SSW/SW quadrant becomes a near-daily feature, and ideal offshore wind is only present 14-16% of the time. Early mornings are the key-before the seabreeze builds, light NE/E winds can keep the 3-5ft (1-1.5m) groundswell clean and punchy. The saving grace is the water temperature, which reaches 17.7-19.7°C, making summer dawn patrols genuinely pleasant. It is not flat, just less consistent and less powerful than the rest of the year.