Surf forecastStatisticsHistorical report

Blaketown Wedge seasonal overview

Best Surf Season (June - August)

Winter roars to life across the West Coast of New Zealand's South Island, and Blaketown Wedge feels the full force of the Roaring Forties. During these months, the Tasman Sea acts as a swell-generating machine, churning out consistent, long-period groundswells from the W and WSW. High-pressure systems drifting south of the continent lock in stable offshore winds from the SW and S quadrants, creating peaky, clean waves that wrap beautifully around the wedge. Average heights hover around a solid 2.0m with periods regularly pushing past 12 seconds, setting the stage for powerful, rippable walls. This is prime time – expect pumping conditions with a high frequency of clean surf.

Fair Surf Season (April - May & September - October)

The shoulder seasons bring a mix of the old and new as the atmospheric circulation transitions. April and May still benefit from lingering winter energy - swell heights remain robust (1.8-2.0m) and periods stay in the 12s range. However, the waxing and waning of subtropical highs means more variable winds, with ideal offshore conditions dropping to around 50-60% of the time. September and October see a resurgence of storm activity in the Southern Ocean, keeping average swell tall, but the trade-off is an uptick in onshore nor'westers as low-pressure troughs roll in. You'll need to pick your windows carefully, but when the synoptics align - typically with a strong high centered south of the Island - the Wedge fires with groomed, long-period walls under sunny skies.

Low Surf Season (November - March)

Summer brings a dramatic shift. The subtropical ridge strengthens, pushing the storm track farther south and reducing the frequency of quality swell. Average heights drop to 1.6-1.8m and periods shorten to 11-11.5s, resulting in a higher percentage of weaker, wind-affected waves. More critically, the prevailing wind regime turns hostile: the classic nor'west pattern (W, WNW, NW) becomes dominant, ripping the surface to shreds and making the Wedge mostly unrideable. While early summer (Nov-Dec) and late summer (Feb-Mar) can still offer the odd pulse from a passing front, expect inconsistent surf and a lot of time spent watching the wind sock. Groveling conditions prevail – this is the season for a longboard or a soft-top.

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Conditions at Blaketown Wedge in September

September: Spring Transition

September marks a change as spring begins to exert its influence. Swell heights actually peak for the year at 2.1m average, with a period of 12.3s – the waves are powerful. However, the ideal wind percentage drops to 46%, signaling the return of less stable synoptics. The swell mix shifts: W direction becomes more prominent (25.1%) alongside the ever-present WSW (31.3%). The wind pattern shows a resurgence of nor'westers: W (9.7%), WNW (6.9%), NW (5.9%), and NNW (5.1%) combine for 27.6% of all winds – significantly higher than winter. The offshore ESE (17.6%) and E (10.3%) are still frequent but less dominant. This creates a mixed bag: on some days you’ll get XL waves with onshore chop, on others you’ll score groomed, long-period runners. It’s a month for the dedicated surfer who is willing to wait for the perfect window.

Average Spot conditions at Blaketown Wedge 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 Blaketown Wedge 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 Blaketown Wedge for your next trip in September.

Ground swell

Ground swell by size

Wind conditions

Evaluate the wind and swell alignment at Blaketown Wedge 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 Blaketown Wedge.

Swell with good wind

Swell with good wind by size