Cap Sim - surf spot statistics

Best Surf Season (November - February)

The heart of the North Atlantic winter delivers the most consistent and powerful swells to Cap Sim. With average heights hovering around 2.2-2.3m and periods frequently exceeding 12 seconds, these long-period pulses from NNW and NW pack serious punch. The key is timing: when high pressure sets up over Europe, the resulting northerly to northwesterly flow (NNO to O) keeps conditions offshore and the waves glassy. Combined with a 50%+ window of favorable wind, this is when Cap Sim shows its true potential.

Fair Surf Season (March - April & September - October)

As the jet stream begins its seasonal shift, the swell becomes less consistent and the wind patterns more fickle. March still sees decent 2.2m swells with 12s periods, but offshore wind reliability drops to 40%. April is a game of patience: solid 2.0m swells from the north are frequent, but the wind turns side-offshore more often. On the other side of summer, September and October mark the return of tropical storm activity and early North Atlantic lows, bringing 1.6-1.8m waves with improving period (10-11s) and a steady rise in offshore wind days (45-49%). These months offer quality sessions without the winter crowds.

Low Surf Season (May - August)

The summer pattern is dominated by the Azores High, which pushes the storm track north and leaves Cap Sim in a swell shadow. Average wave heights drop to 1.6-1.7m and periods shorten to 7-9s, resulting in weaker, more wind-swell oriented surf. The thermal gradient forces a strong northeasterly trade wind (NE to NNE) that is often too onshore for the west-southwest facing beach. Offshore wind windows shrink to just 23-30%, making clean conditions a rarity. While there are occasional pulses from summer storms, most days are small, choppy, and best suited for a longboard or a groveler.

April: Spring Mix

April sees a noticeable drop in average wave period to 10.8s, though heights remain a respectable 2.0m. The dominant swell direction shifts even more towards the north: NNW accounts for a whopping 47.1% of all swell, with NW at 20.6%. This means the swell is even more northerly, reducing the quality of the refraction into the bay. Offshore wind conditions are the worst of the year so far, at only 31% ideal. The trades are strong and persistent – NE (26.3%) and NNE (27.3%) winds dominate, often blowing too hard and from the wrong angle. However, occasional cut-off lows in the eastern Atlantic can produce that rare combination of solid WSW swell and light offshore northerlies. When that happens, the waves can be excellent, but patience is required. Expect a mix of fun-sized waves and less favorable chop.