Wainui Beach • Statistics for December

December: Early Summer Doldrums and Cyclone Swell

December settles into the early-summer pattern at Wainui Beach. Average swell height sits at 5ft (1.5m), the average period is the shortest of the year at 9.6 seconds, and ideal offshore winds occur just 41 percent of the time. The good news is that the swell direction spectrum still has a strong E/ENE/SE component, especially the ENE swell at nearly 14 percent and E at over 12 percent, so the beach remains exposed to whatever energy is running. Most surf falls into the 3-5ft (1-1.5m) and 5-6.5ft (1.5-2m) categories, with almost nothing passing the 8ft (2.5m) mark outside of a tropical event. Afternoon seabreezes from the NE/E are the main spoiler, and the early-morning NNW/NW offshore is often the only clean window of the day. Water temperature climbs to 17.6°C, air temps average 17.5°C, and rainfall is low at 2.22mm per day. A South Pacific cyclone can occasionally deliver an unexpected E/ESE swell that turns December from average to epic - otherwise treat it as a small-wave summer month.