Surf forecastStatisticsHistorical report

The Island seasonal overview

Best Surf Season (March - May)

New Zealand's autumn delivers the sweet spot for The Island. As the South Pacific transitions from the summer lull, extratropical lows begin to intensify, sending consistent, long-period swell from the south quadrant. March through May sees average wave heights climbing to 1.8-1.9m with periods over 10 seconds, while offshore wind patterns from the north and northwest appear over 46% of the time. This is when the sandbanks hold their shape best, and we get those glassy, rippable morning sessions with punchy lines.

Fair Surf Season (June - October)

The winter months bring the biggest swells but with a trade-off. June through August sees average heights peaking at 2.1m and periods around 10.9s, thanks to powerful storm systems in the Southern Ocean. However, the wind is ideal only 45-49% of the time, as stronger cold fronts push though with S/SW winds that can ruin the wave face. Spring (September-October) sees a slight drop in size to 1.6-1.7m but an improvement in wind consistency, with offshore flow from the NW quadrant becoming more frequent. It's a season of variety — you might score epic, long-period groundswells under sunny skies, or battle choppy onshores.

Low Surf Season (November - February)

Summer at The Island is the quietest time. From November to February, persistent high-pressure over the Tasman Sea reduces storm activity, leading to average swell heights of just 1.5m and periods around 9.6-9.8s. While the wind is ideal 44-47% of the time, the swell is often from the east and northeast — directions that don't wrap in well to the S-SE facing beach. You'll get plenty of small, groveling days, and the occasional fun-sized 1m wave, but if you're after real power, this is not your window.

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Conditions at The Island in September

September: Spring Swing

September marks the start of spring, with average swell height dropping to 1.7m and period to 10.5s. Swell direction is mixed: S remains the largest at 18.8%, but SSE drops to 12.3%, and easterly swell (E, ESE, SE) increases. The 1.5-2.5m range from S is still present (6.5% in 1.5-2m, 4.2% in 2-2.5m), but there is more small swell. Wind is ideal 49% of the time — tied with May — due to strong NW (13.7%) and WNW (13.2%) patterns. These spring NW winds often bring sunny skies and clean conditions. The swell is slightly less powerful than autumn, but the frequency of good wind days is high. It's a great month for getting long, fun rides without the extreme size of winter.

Average Spot conditions at The Island in September

Swell history for September

0 - 0.5
0.5 - 1
1 - 1.5
1.5 - 2.0
2.0 - 2.5
> 2.5 m

Wind history for September

0 - 10
10 - 20
20 - 30
30 - 40
40 - 50
> 50 km/h

Swell quality

Analyze the groundswell consistency at The Island during September. Based on historical data, there is a % probability of groundswell occurring this month. The chart below provides a detailed breakdown of the average wave height distribution, offering deep insights into the swell quality and surf potential you can expect at The Island for your next trip in September.

Ground swell

Ground swell by size

Wind conditions

Evaluate the wind and swell alignment at The Island for September. Our analysis shows that favorable offshore or side-shore winds coincide with surfable swell approximately % of the time. The accompanying graph illustrates the average size distribution of waves during these optimal wind windows at The Island.

Swell with good wind

Swell with good wind by size