Whale Beach • Statistics for September

September: Transitional Spring Mix - Still Plenty of Good Surf

September marks the turn toward spring. Ideal wind drops to 47%, but there are still plenty of workable days, especially in the early mornings. Wind distribution shows a fading W/NW influence, with NW 9.0%, W 8.8%, WNW 9.4% and WSW 7.1%, while the NNW component grows to 11.7%. Swell directions spread between east and south: SSE 20.8%, S 13.6%, SE 13.7%, E 10.7%, ESE 10.8% and ENE 11.4%. Average height is 1.3m (4.3ft) and average period drops slightly to 8.9s, meaning a bit less power than winter, but the swell direction is closer to the optimal ENE/E/ESE/SE window. Expect a mix of summery east trade swell and wintery south groundswell. Water temp is 18.2°C, air temp 15.6°C and rainfall is about 1.7mm/day. There are great days in September, particularly when a Tasman low parks off the coast and feeds steady E/SE swell under a light W/NW morning flow.