Capao da Canoa • Statistics for September

September: Big Swell, Shifty Wind

September produces the largest average swell of the year at around 6ft (1.8m), and there is real size in the mix -- ENE, E, ESE, SE and S all have meaningful 6.5-8ft (2-2.5m) percentages. The average period of 9.1s means these are powerful, punchy waves, often with a long-period component from early spring frontal systems. The directional spread is broad, but the E through SSE window still accounts for about 55 percent of the swell, so Capao da Canoa is well exposed.

However, September also marks the return of the trade winds. NE jumps back to 23.4 percent and ENE adds 13.1 percent, pushing the ideal wind score down to 21 percent. Offshore W/NW flow remains scarce at just under 10 percent. That often puts a lump on the waves' shoulders, and you need to chase the early-morning windows or pre-frontal NW breezes. Water temperature starts to recover at 16.9°C, air temperatures average 15.8°C (ranging from 4.9°C to 29.6°C), and rainfall reaches 4.94 mm/day.