Praia do Silveira • Statistics for September

September: The Season's Peak Swell Size

September produces the largest average swell of the year at 1.5m (5ft), with the period still a solid 9.2s. This is the early spring transition, and the South Atlantic remains very active. E swell dominates at 20.8 percent, followed by ESE (19.1 percent), ENE (18.4 percent), and SE (15.4 percent)-an excellent directional mix for Silveira's ESE-facing beach. What makes September stand out is the distribution: the 1.5-2.5m range is heavily populated, with E (6.5 percent), ESE (6.5 percent) and ENE (5.2 percent) all pumping, and even the S direction delivering 2.1 percent in the 2-2.5m range. The raw power is there. The downside is wind. As spring warms the continent, the pressure gradient tightens, and NNE winds blow 22.5 percent of the time. Ideal conditions drop to 22 percent. SSW winds at 15.9 percent offer some relief, but the offshore westerly windows grow shorter. Air temps average 17.0°C and water temp is 18.5°C. September gives you the size; the challenge is finding one of the clean, west-wind mornings to enjoy it.