Umdloti • Statistics for September

September: Spring Mix - Good Swell, Rebuilding Trades

September is a transition month in the true sense. The average period drops to 9.6s, average height remains 1.8m, and ideal wind falls to 34%. The ocean is still full of winter energy: S 19.4%, SSE 17.3%, SE 14.5%, ENE 13.7%, E 13.5% and ESE 12.5%. The S component retains its 6-8ft (2-2.5m) juice, but ENE swell is also building, with 5.2% of all observations in the 2-2.5m range. That shows the transition from pure Southern Ocean swells to more east-based, warmer-water swell sources. The wind is less reliable. NE returns as a strong 14.0%, ENE is 9.0%, SSW 15.9%, S 10.2% and SW 8.6%. The offshore W/WNW/NW signal is still present but no longer dominant. Air temp warms to 19.9°C, water is around 21.2°C, and rainfall increases to 1.46 mm/day. September can still pump - particularly in the wake of a cold front - but you have to be more selective.