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 February typically offers consistent but relatively small surf, with an average swell height of 0.8m and a solid 13.9s period, indicating clean and well-spaced waves. The majority of swell comes from the SSW, SW, and WSW directions, with the most common wave heights falling in the 0.5-1m range (around 60% combined). Bigger sets in the 1.5-2m range are less frequent but do occur, particularly from WSW. Wind conditions are favorable about 35% of the time, with light offshore breezes from the north and northeast being the most ideal for shaping up the waves. However, onshore winds from the south and southwest can occasionally disrupt conditions, especially at higher speeds (20-30kph). Overall, expect small to medium, clean waves with decent shape, but larger swells are rare—ideal for performance surfing on smaller days and more challenging but fun sessions when the swell picks up.