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.

September at Lower Trestles offers consistent but generally smaller swell conditions, with an average height of 0.8m and a solid 15.0s period, indicating clean, well-spaced waves. The majority of swell energy comes from the SSW (62.12% of waves in the 0.5-1m range) and SW (19.82% in the same range), ensuring favorable direction for this break. Larger swells above 1.5m are rare, occurring only around 0.11% of the time, meaning sessions are mostly manageable and less likely to get unruly. Wind conditions are surfable 40% of the time, with the most frequent issue being WSW winds (7.5% at 10-20kph), which can create minor texture. Calm or light winds (0-10kph) prevail from the W and WNW, but stronger afternoon breezes occasionally disrupt sessions. Overall, September delivers mostly fun, rippable waves with decent shape, though not as powerful as other seasons—ideal for performance surfing with occasional small, clean days.