Altura - surf spot statistics

Altura, Portugal, offers the most consistent surf conditions during the winter months, particularly from November to February. During this period, the swell activity is at its peak, with ground swell percentages improving significantly—up to 21% in January and 20% in December—while wind swell contributes an additional 35-42%. The average swell size hovers around 0.7m, occasionally reaching up to 0.8m in December, providing the most rideable waves of the year. However, wind conditions remain challenging, with bad onshore winds (87-89%) dominating, making clean sessions a rarity. Spring (March-April) sees a decline in ground swell but still maintains decent wind swell activity (41-48%), though wind conditions remain unfavorable. Summer (May-September) is the least consistent, with minimal ground swell (0-4%), weak wind swell (25-45%), and very high percentages of flat days (61-74%). The swell size drops to 0.4-0.6m, and wind conditions worsen further (90-94% bad winds). Autumn (October-November) marks a gradual return of swell energy, with ground swell increasing to 6-9% and wind swell around 37-43%, but wind quality remains poor. For experienced surfers, the best windows are likely in late autumn and early winter when swell consistency improves despite the persistent onshore winds. If you prioritize quality over frequency, December stands out with the largest average swell size and slightly better wind odds (13% clean conditions). Summer is only suitable for beginners due to small, weak waves, while winter offers the most powerful—albeit inconsistent—surf.