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.

December: Summer's Slumber

December marks the official start of summer and the low point of the surf year. Average swell height is 2.3m with a period of 11.7s – the smallest and weakest of the year. Swell direction still favors SW (35.5%) and WSW (13%), delivering solid groundswell that is often undermined by onshore winds. The offshore wind percentage hits a yearly low of 22%. Wind patterns show a large chunk of S and SW winds (20% combined) that spoil the wave face. However, the easterly quadrants (E to ESE) account for 16% of the wind, mostly light, offering occasional cross-offshore conditions in the morning. December is a month for dawn patrols and a summer-friendly shortboard. The crowds hit the water, but the quality is marginal. Keep an eye out for a rare Tasman low that can briefly energize the ocean.