Sines - surf spot statistics

Best Surf Season (October - March)

Winter brings the Atlantic to life, with average swell heights consistently over 2m and periods averaging 12-13 seconds, delivering powerful, long-period groundswell. Although the dominant swell direction is from the NW (which doesn't directly hit the south-facing beach), the frequent passage of strong extratropical cyclones dragging fronts across the Iberian Peninsula often produces pulses of S-SSW-SW swell that wrap perfectly into Sines. Combined with a higher incidence of offshore winds from the north quadrant (N, NNE, NE, NNW), the result is a 50-52% chance of ideal conditions. This is the prime window for pumping, firing waves in the 1.5-2.5m range, and occasionally XL days when the Atlantic aligns.

Fair Surf Season (April & September)

During the transition months of April and September, the storm track starts to shift, yet the ocean remains active. Average swell heights drop to 1.8m (April) and 1.4m (September), with periods around 11 seconds – still yielding solid, rippable waves. The Azores High begins to build or retreat, leading to a more mixed wind regime. Offshore winds from the north still dominate about half the time, but onshore southerlies become more frequent. These months are a classic gambler's window: you might score a clean, long-period SW swell with light N winds, or you might face smaller, choppier conditions. Best for the intermediate surfer looking for fun waves without the winter crowds.

Low Surf Season (May - August)

The summer months are defined by a strong Azores High, which suppresses the Atlantic storm machine. Average swell heights bottom out at 1.3m and periods slip to 8-9 seconds – small, fun-sized waves that require a grovel board. The upside is wind quality: with the thermal low over the Iberian Peninsula, north winds blow consistently, making offshore conditions (N, NNE, NW, NNW) the norm. In fact, ideal wind percentages peak at 55-61% in this period, meaning many days deliver clean, micro-to-small surf. While you won't chase XXL swells, this is the season for quiet morning sessions with smooth, rippable lines, especially on a longboard or fish.

October: The Season Ignites

October marks the true start of the best surf season. Average swell height jumps to 1.8m, period to 11.4s – solid, long period groundswell is back. The wind ideal percentage is 54%, with N (11.0%) and NNW (12.1%) winds common, though southerly winds (S, SSW, SW) increase their presence (totaling about 17.3% – keep an eye on these as they can be onshore). The swell direction is still predominantly NW (39.1%) and WNW (24.5%), but the optimal S to SW swell combination now accounts for 1.7% – a meaningful increase. The North Atlantic roars to life during October as the number of strong extratropical storms increases sharply. When the right combination of a low pressure system tracking south and a high pressure ridge building in produces S/SW swell with north winds, the surf at Sines is epic. This is a prime month for pumping, firing sessions.