Predictions: NOAA CO-OPS station 9414131 — heights relative to MLLW.

Harmonic prediction from the official tide authority. Very high accuracy under normal conditions; storm surge may shift actual water level. Not for navigation.

Predictions: NOAA CO-OPS station 9414131 — heights relative to MLLW. · Not for navigation.

The angler tradition that rates each day for fish-bite likelihood using moon transits and rise/set. One to five stars, not a scientific forecast.

• Mon
  ★★★★★
• Tue
  ★★★★★
• Wed
  ★★★★★
• Thu
  ★★★★★
• Fri
  ★★★★★
• Sat
  ★★★★★
• Sun
  ★★★★★

Next spring tide on Fri 01 May (range 1.9m / 6.3ft). Last neap on Sun 26 Apr. Next neap on Sat 09 May.

Spring tides cluster around new and full moons (biggest swings). Neap tides land on quarter moons (smallest swings). See the spring tide and neap tide glossary entries for the why.

Half Moon Bay sits on the open Pacific coast of San Mateo County, about 50 km south of San Francisco, with the working harbour at Pillar Point on its northern shore and the long sand of Surfer's Beach, Miramar, and the Half Moon Bay State Beaches running south to the Tunitas Creek mouth. Pillar Point itself is the point of land that gives the harbour its breakwater, and just outside the breakwater is the offshore reef called Mavericks — one of the world's most serious big-wave surf breaks, working in winter on solid northwest groundswells with faces routinely topping 15 metres. The tide signature here is the open Pacific mixed-semidiurnal signal that the entire California coast shares — two highs and two lows of unequal size each day, the bigger swing falling on the lower-low water — with a moderate range. Mean range at the Pillar Point gauge is about 1.6 metres, climbing past 2.1 metres on spring tides and dropping near 1.0 on neaps. The local tide signature matters more for surf reading than for navigation: Mavericks works best at lower stages of the tide when the reef edge stands proud, and the inside breaks at Surfer's Beach reshape across each cycle. The harbour itself stays workable across the cycle for the commercial fishing fleet running out for Dungeness crab in winter and salmon in summer, and for the recreational charter boats heading offshore. Lowest spring lows around new and full moons open the rocky intertidal at Fitzgerald Marine Reserve just up the coast at Moss Beach for hours either side — one of the better protected tide-pool zones on the central California coast. Pacific storm surge from winter lows can shift apparent water level 10 to 20 cm above predicted; harmonic predictions assume calm. NOAA CO-OPS station 9414131 supplies the gridded predictions on this page.