Johanna - surf spot statistics

Best Surf Season (May - September)

The Southern Ocean fires on all cylinders from May through September, delivering Johanna's most consistent and powerful swell. Average wave heights climb to the 2.6-2.9m range with periods hovering around 13 seconds – that's long period, groundswell territory. The dominant SW and WSW energy slams straight into this SSW-facing beach, producing hollow, rippable walls. Winter's strong frontal systems and deep low-pressure cells spinning up near Antarctica are the driving force. Offshore winds from the N, NNE, and NE occur roughly 30-35% of the time, often aligning with post-frontal high-pressure ridges. When it all comes together, you get pumping, firing surf with clean, offshore texture.

Fair Surf Season (April & October)

April and October serve as transitional windows where the swell quality remains high but consistency and wind reliability take a small step back. April still pumps out an average 2.5m swell at 12.7s, with a solid 33% offshore wind score – one of the best wind percentages of the year. October sees the swell start to wind down (2.7m, 12.6s) and the offshore wind window drops to 25%, but the predominant SW/WSW swell still offers plenty of fun, solid waves. These months can dish out epic days when a late-season storm aligns with a northerly breeze.

Low Surf Season (November - March)

The summer months from November through March bring the smallest average surf of the year (2.3-2.4m, 11.7-12.0s), though even these numbers are respectable by many standards. The real issue is the dominance of onshore winds from the S, SW, and WSW – the same directions that bring the swell – which create bumpy, chop-ridden conditions. Ideal offshore wind percentages drop to 22-25%. The swell still rolls in from the SW and WSW, but periods are shorter and the wave heights often sit in the 1-2m fun-size range. It's not a write-off: early mornings or days with a strong inland heat trough can produce brief offshore windows, but overall consistency and quality take a seasonal dip.

July: Depth of Winter

July is statistically the biggest month for swell on the Australian south coast. Johanna averages 2.8m at 13.0s, with a notable increase in WSW swell (17%) and a slight rise in W energy (7%). This means more westerly swell angles that wrap directly into the cove. Ideal offshore wind drops to 30% as the wind rose becomes more volatile: N and NNW combine for 26%, but strong W and WNW winds also increase (10% and 10% respectively), which are cross-onshore. The Southern Ocean is at its angriest, producing XL swells (>2.5m) about 4% of the time. These are massive, charging-size waves best left to experienced big-wave surfers. The offshore windows are narrower but when a high-pressure system clears the sky and the wind goes light N, Johanna can offer some of the heaviest, cleanest waves of the year.