Upper Trestles • Statistics for December

December: Prime Trestles, Groomed by Offshore Flow

December is the statistical peak for surface quality at Upper Trestles. The average height is 3ft (1.0m), the period is 12.6s, and ideal wind conditions are present an outstanding 59% of the time, the highest of the year. The wind profile reads like a textbook offshore forecast: NE 24.7%, NNE 10.5%, N 2.5% and ENE 5.4%. Onshore S/SSW/SW/WSW flow is suppressed to about 20%, leaving the SSW-facing break clean and organized for hours. Swell direction is dominated by W at 54.6% and WSW at 28.9%, with SW at 10.6%. The common size is 2-3ft (0.5-1m) and 3-5ft (1-1.5m), but stronger W systems can push 5-6ft (1.5-2m) and occasionally bigger. Water temperatures are chilly at 14.6°C, air averages 13.1°C, and rainfall is active at 1.70 mm/day. Storm fronts may throw some rain days at you, but December offers the best chance for glassy, long-period, firing Upper Trestles.