Coastal weather across San Mateo County features calm morning conditions transitioning to standard localized onshore flow, with high temperatures today reaching 64°F along the coast and dipping to overnight lows of 51°F. Light morning winds are increasing out of the northwest at 5 to 10 knots this afternoon, which is helping to gradually clear out lingering blocks of patchy dense coastal fog.
Regional wave sizes are holding at an approachable average of 3 to 5 feet inside the primary marine zones. Ocean buoys near Half Moon Bay reveal a mixed sea state dominated by a primary northwest swell running at 5 feet with an 8-second period, which is cleanly blending with a secondary long-period southern swell measuring 3 feet at 15 seconds.
Tidal movements at Princeton Harbor show a dynamic afternoon fluctuation for beachgoers and mariners. A low tide of 1.81 feet occurred at 12:09 PM, which is currently reversing into a prominent 5.53-foot high tide scheduled for 6:45 PM this evening, before dropping out to a final low tide of 0.47 feet in the early morning hours of Wednesday.