Lower Trestles - surf spot statistics

Lower Trestles is a consistent surf spot with predominantly ground swell year-round, though the optimal conditions vary across seasons. The best months for surfing are typically from March through September, when ground swell occurrence is highest (82–96%) and swell size averages around 0.8–0.9m. However, wind conditions play a crucial role, with onshore winds (bad conditions) dominating most of the year. The most favorable wind conditions are found in September and October, when good wind percentages reach 40%, though even then, offshore winds remain a minority. Late spring and early summer (May–June) see the strongest swells (0.9m), but wind quality drops significantly (only 26% favorable). Winter months (November–February) offer slightly better wind ratios (32–36% good), but swell consistency and size decrease, with more no-swell or wind-swell days. Ultimately, September and October strike the best balance, combining reliable ground swells (89–95%) and the least unfavorable winds (40% good), while still maintaining decent swell heights around 0.7–0.8m. For surfers prioritizing clean conditions over raw swell size, these transitional months are the most dependable.

March at Lower Trestles offers relatively consistent but smaller surf, with an average swell height of 0.8m and a solid 14.3s period, indicating well-spaced, clean waves. The predominant swell comes from the SSW and SW directions (accounting for over 60% of waves in the 0.5-2m range), favoring the spot’s natural setup with groomed, rippable walls. About 33% of days have favorable offshore or light wind conditions, typically during morning sessions before WSW or W winds pick up (6-20kph range), which can create choppier conditions as the day progresses. While larger swells over 2m are rare (occurring less than 1% of the time), the majority of waves fall in the 0.5-1.5m range—ideal for performance surfing with occasional overhead sets on the best days. Expect a mix of glassy mornings and occasional afternoon onshore breezes, with SW/W swells providing the most rideable energy. Solid intermediate to advanced conditions prevail, but bigger days require precise positioning due to the spot’s technical nature.