Umdloti • Statistics for May

May: Winter Swell Engine Turns On

May is when winter takes hold. The average wave height holds at 5-6ft (1.7m), but the period pushes up to 10.4s and ideal wind reaches 54%. The swell direction shifts hard toward the south: S swell is now 21.9%, SSE 19.0%, SE 15.6%, E 15.2% and ESE 12.9%. A greater share of S and SSE swell arrives in the 5-8ft (1.5-2.5m) category, a sign of strong frontal activity below the continent. The wind pattern changes dramatically. The NE trade is still present at 11.1%, but the offshore north-westerly flow is now a major feature: WNW totals 9.2%, NW 8.6%, W 5.2% and WSW 5.2%, with NNW (9.8%) and SW (8.8%) filling in. This is the classic pre-dawn offshore regime. Air temps cool to 20.6°C, water drops to 23.4°C, and rainfall falls to 0.94 mm/day. In May, Umdloti starts to offer regular, clean, lined-up surf - especially on the morning tide.