Upper Trestles - surf spot statistics

Upper Trestles is a high-quality surf spot that benefits from consistent ground swell year-round, though the best conditions are typically found between April and October. During these months, ground swell dominates (90%+ of the time), with minimal wind swell interference, making for clean, well-organized waves. The mean swell size hovers around 0.8-0.9m, providing ideal conditions for performance surfing. However, wind conditions are often less favorable, with bad onshore winds occurring 60-75% of the time, peaking in May and June. The late summer and early fall months (September-October) offer slightly better wind conditions, with good winds around 38-39% of the time, improving wave quality despite the swell size tapering slightly. Winter months (November-March) see more variability, with increased wind swell and no-swell days, while ground swell remains strong but less reliable. December and January have the highest chance of no swell (25-31%) and the smallest average wave heights (0.7m). For the best balance of swell consistency and manageable wind conditions, September and October stand out, though dedicated surfers can find good waves from late spring through early fall if willing to work around the frequent onshore winds.

Upper Trestles in March typically offers clean but somewhat inconsistent surf conditions, with an average swell height of 0.8m and a favorable period of 14.3s, indicating long-period energy that helps produce quality waves when paired with the right wind. The dominant swell directions are SSW and SW, contributing over 75% of the waves in the 0.5-1.5m range, with occasional bigger sets up to 2.5m when WSW and W swells arrive. The wind is rideable only 32% of the time, primarily when it’s light (under 10kph) and offshore from the NNE to ENE or calm. Onshore winds from the WSW to W are more common and can degrade conditions, especially when exceeding 20kph, which happens frequently. Expect smaller, rippable waves on most days, with occasional punchier peaks when the SW swell mixes with good wind alignment. Overall, March requires patience—it’s not the most consistent month, but when conditions align, Upper Trestles can still provide fun, high-performance walls.