Itapeva • Statistics for December

December: Early Summer Chop

December marks the official return of summer, and Itapeva feels it. Average swell height drops to 1.5m (5ft), the period sinks back to 8.2s, and the ideal wind percentage is only 19 percent. The trade-wind machine is running again, with NE at 26.6 percent, ENE at 14.9 percent and NNE at 12.5 percent. The swell direction is still dominated by the E quadrant - E at 22.8 percent, ENE at 22.1 percent, ESE at 17.0 percent, SE at 13.6 percent, SSE at 11.9 percent - but most of that energy is short-period windswell generated locally rather than true groundswell. The onshore E, ESE, SE and SSE wind component is around 17.6 percent, which further degrades quality. Water temperature is 22.1°C and air averages 21.3°C, making it pleasant for a swim but not ideal for Itapeva's best waves. The best chance for good surf comes at dawn, when onshore winds are weakest, or when a rare early-summer cold front sweeps in with NW winds and a solid E/SE pulse.