Mossel Bay seasonal overview
Best Surf Season (October - March)
During the Southern Hemisphere summer, Mossel Bay comes alive with the most favorable blend of conditions. From October through March, the region experiences a climatological peak in the frequency of offshore winds from the south (SSO, S, SSW, SW). This is when the wind is ideal roughly 40-49% of the time, allowing the dominant south and southwest swell to wrap into the north-facing bay with a surprisingly clean, groomed face. The average wave height sits at a solid 2.0m ( 6-7 ft) with a long period of 10.6-11.2 seconds, delivering a punchy, rideable wave that can be rippable on the better days. The lack of direct north swell is a limitation, but the southerly energy, when combined with these offshore winds, creates a fun and good surf zone, especially at the protected ends of the beach.
Fair Surf Season (April - May & September)
April, May, and September represent the transition periods, where the surf potential becomes a bit more fickle. The ideal wind frequency drops to 30-39%, meaning more days are plagued by onshore winds from the north and east that ruin the wave quality. The swell energy actually increases – heights average 2.1-2.3m with very powerful periods of 11.5-12.1 seconds – but these are almost exclusively from the south, making them more difficult to line up on this north-facing shore. When a strong low-pressure system stalls over the Southern Ocean, it can pump in a long-period, heavy groundswell, but the chance of glassy offshore conditions shrinks significantly. It is a season of averages and punchy waves if you score a rare window of light south wind.
Low Surf Season (June - August)
The winter months – June, July, and August – are the most challenging for surfing Mossel Bay. The swell is at its peak, with an average height of 2.3-2.4m and a very long period of 12.0-12.3 seconds – often producing epic, heavy energy out at sea. However, the wind is ideal only 23-28% of the time. The prevailing wind pattern shifts, with strong onshore flows from the north, northwest, and west dominating the region. This creates a messy, choppy surface that demolishes the wave quality. The south-oriented swell wraps in but is constantly battered by onshore winds, resulting in poor and unenjoyable surfing at most spots. Occasional brief windows with south winds can produce very powerful waves, but they are rare and highly unpredictable.
Loading chart...
Conditions at Mossel Bay in December
December: Prime Summer Surf
December rounds out the year with excellent summer conditions. The average swell height is 2.0m, period 10.6s – fun-sized to good. The swell direction is dominated by SSW (27.5%) and SW (19.4%), with S (13.9%) also present. The ideal wind percentage is 45%, with the wind pattern showing strong E (18.2%) and ESE (18.8%) flows, but also frequent SW (10.7%) and WSW (10.7%) winds that are offshore for this north-facing beach. The wave height distribution shows a concentration in the 1.5-2.5m range – pumping when the combination of south swell and south wind aligns. It's a classic summer month for scoring consistent, quality waves.
Average Spot conditions at Mossel Bay in December
Swell history for December
Wind history for December
Swell quality
Analyze the groundswell consistency at Mossel Bay during December. 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 Mossel Bay for your next trip in December.
Ground swell
Ground swell by size
Wind conditions
Evaluate the wind and swell alignment at Mossel Bay for December. 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 Mossel Bay.
