Seal Beach • Statistics for June

June: Summer Swell, Onshore Wipeout

June is the peak of the onshore season. The wave rose is beautifully aligned for Seal Beach: SW 42.1%, WSW 34.8%, SSW 15.6%, with an average period of 13.9s - one of the longest of the year. In an ideal world this would be pumping surf. But average swell height slips to 3ft (0.9m), and roughly 76% of the energy sits in the 2-3ft (0.5-1m) range. More importantly, ideal wind conditions collapse to a painfully low 1%. The SW wind blows 28.0% of the time, SSW 20.5%, and WSW 18.5%; almost all of it is in the 10-30kph range, creating a persistent onshore chop. The few clean moments happen in the first hour after sunrise before the sea breeze sets in, occasionally coinciding with a long-period SSW groundswell. That vanishing act is what keeps summer surfers on the dawn patrol. Water temp climbs to 16.0°C, air temp averages 17.9°C, and precipitation is essentially nil.