Surf forecastStatisticsHistorical report

Avalanche seasonal overview

Best Surf Season (June - August)

The Southern Ocean roars to life during the austral winter, sending powerful, long-period groundswells marching toward the Western Cape. June through August sees the highest average wave heights (2.3-2.4m) and periods (12.2-12.5s), dominated by SSW and SW swell – directions that wrap into Avalanche's NNE-facing beach. However, this raw power comes at a cost: offshore wind (S through WSW) blows only 18-21% of the time, with frequent E to NE onshore flows messing up the lineup. When a strong winter low-pressure system aligns with a brief southerly wind, the result is pumping, heavy waves with clean faces – the kind that make the long paddle worth it.

Fair Surf Season (April - May, September - November)

The shoulder seasons offer a compromise between size and cleanliness. In April and May, average swell holds at 2.1-2.2m with periods creeping toward 12s, while ideal wind percentages improve to 23-25%. September to November sees similar dimensions (2.1-2.3m, 10.8-11.7s) and offshore wind frequencies around 22-25%. These months are transitional: the Southern Ocean is still active, but high-pressure systems are less dominant, allowing more S-SW wind days. The waves are often fun, solid, and rippable, especially when a passing cold front delivers a clean, glassy window. You won't score the biggest sets, but you'll find more rideable, groomed lines.

Low Surf Season (December - March)

The summer months bring the most consistent offshore wind conditions (28% ideal – the highest of the year), with wind blowing steadily from the S to SW quadrant. Unfortunately, this coincides with the lowest average swell heights (1.9-2.0m) and shortest periods (10.7-11.4s). The predominant SSW and SW swells are still present, but they lack the power and period to generate real punch. December through March is the 'micro season' at Avalanche: you'll often find clean, groomed 1-1.5m waves – fun-sized and groveling – but don't expect any pumping, heavy days. Light offshore winds morning and evening can make for a pleasant surf session, but the lack of any north quadrant swell keeps the spot from firing.

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Conditions at Avalanche in May

May: The Great Southern Pulse

May delivers an average 2.2m swell and a period of 12.2s – the first month of truly long-period groundswell. The swell direction shifts: SSW still leads (28%), but SW jumps to 21% and S falls to 12%. This south-southwest bias is key for Avalanche, as it provides more direct wrap. However, ideal wind drops further to 23%, with increased NW and N winds (5-6% each) and strong W and WNW flows (15% and 7%). North quadrant winds are bad news. The wave heights are solid: 1.5-2.5m accounts for nearly 47% of the frequency. When you get a SSW swell with a SW offshore wind, the waves are powerful, long-period, and clean – the best of the month.

Average Spot conditions at Avalanche in May

Swell history for May

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

Wind history for May

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

Swell quality

Analyze the groundswell consistency at Avalanche during May. 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 Avalanche for your next trip in May.

Ground swell

Ground swell by size

Wind conditions

Evaluate the wind and swell alignment at Avalanche for May. 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 Avalanche.

Swell with good wind

Swell with good wind by size