Antonio's seasonal overview
Best Surf Season (October - March)
As the North Atlantic churns to life with powerful extratropical storms, Antonio's enters its prime window from October through March. The average swell height hovers between 1.2m and 1.6m, with wave periods often reaching 10 seconds or more, translating to punchy, lined-up waves that wrap into the NNW-facing beach. While the percentage of ideal offshore winds (from the south quadrant) sits between 33% and 44% during these months, the sheer power and consistency of N, NNE, and NNW swell make this the go-to period for experienced surfers. When a strong low-pressure system tracks east of the coast, we see long-period NW groundswell that can push into the 1.5-2.5m range, creating firing conditions. The trade-off is that the wind is often onshore from the NE or ENE, so you have to pick your days carefully—but when the wind swings south, the reward is epic.
Fair Surf Season (April, May & September)
These transition months see the jet stream begin to shift northward, reducing the frequency of powerful storms. Average swell heights drop to 1.1-1.3m, and wave periods shorten to 8.7-9.6s, bringing more fun-sized, rippable surf rather than heavy barrels. The upside: the percentage of offshore winds climbs to 50-63%, offering cleaner conditions more often. For April and May, the dominant swell still comes from the NE-ENE quadrant, but occasional NNE pulses can deliver decent shape when the wind cooperates. September marks the beginning of the autumn ramp-up, with the first real groundswells of the season starting to appear—though they are still inconsistent compared to the heart of winter. These months are ideal for logging sessions on a groveler or shortboard when the swell is small, but you won't want to put your step-up away completely.
Low Surf Season (June - August)
Summer brings a dramatic shift: the North Atlantic storm track retreats far to the north, leaving Antonio's starved for consistent swell. Average wave heights barely scrape 1.0m, and periods plunge to 6.7-7.3s, resulting in mostly choppy, low-energy waves that are often too small and crumbly for any real surfing. The swell direction is almost exclusively from the ENE and E, which means the waves are heavily shadowed and lack any of the power or shape that N and NNW swells provide. The one saving grace is the wind: offshore wind percentages are still high (51-68%), so if you have a stand-up paddleboard or a foamie, you can find some fun on a glassy day. But for anyone expecting real surf, this is the time to travel or focus on other water sports. Occasional tropical storms or hurricanes can inject a fleeting pulse of swell, but those events are rare and often accompanied by unfavorable winds.
