Manasquan Inlet • Statistics for December

December: Winter Locked In and the Holiday Swell Train

December is prime time at Manasquan. The average height remains 4ft (1.3m), the period stays around 7.1s, and the frequency of active lows along the Eastern Seaboard is high. The swell rose is broadly spread, with S and SSW still showing from before frontal passage, but E, ESE, SE, ENE and even W/NW swells all chipping in to keep the ocean alive. The wind is classic winter: WNW is the single dominant direction, followed by W, NW and NNW, which means offshore flow is the rule, not the exception. At 32 percent ideal wind, the setup is consistent. This is the time when a negative NAO can really align the Eastern Seaboard with a conveyor belt of cold-latitude storm systems, sending 10-15s groundswell into the beach while the wind howls offshore from the northwest. Water temperatures drop to 9.2°C and air averages 5.9°C, so winter rubber is mandatory. But when the tide and swell align, Manasquan Inlet can be one of the best and heaviest waves on the New Jersey coast.