Kohala Lighthouse • Statistics for March

March: Late-Winter Swell With a Trade-Wind Catch

March is a transition month disguised as winter. The average height still reads 1.8m (6ft), but the period has slipped to 11.5s and the direction mix has shifted noticeably toward the east. ENE/E swells now account for 58% of all swell energy - with ENE alone at 35.1% and a significant share of waves in the 1.5-2.5m (5-8ft) range - while the optimal north quadrant shrinks to roughly 28%. What this means at Kohala Lighthouse is simple: there is still plenty of size, but it is increasingly coming from a direction that doesn't hit the north-facing reef cleanly. Trades blow hard, with ENE/E winds combining for 75.6% of the month, and ideal surf wind drops to 10%. March also marks the wettest month on the data set at 4.42 mm/day, a reminder that the tail end of the wet season is still active. When a late-season low tracks north and drags a southwesterly breeze over the bay, the lighthouse can still fire. You just have to pick your windows more carefully.