Predictions: Open-Meteo Marine (MeteoFrance SMOC, 0.08° grid) — heights relative to MSL (not chart datum / LAT). Model-derived.

Model-derived from a global ocean grid. Useful indication; expect about ±45 minutes on average vs. a local harmonic gauge, individual stations vary widely. See /methodology for per-region detail. Not for navigation.

Conditions as of 12:00 local time. Refreshes daily.

Predictions: Open-Meteo Marine (MeteoFrance SMOC, 0.08° grid) — heights relative to MSL (not chart datum / LAT). Model-derived. · 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 6.0m). Last neap on Sun 26 Apr. Next neap on Sat 02 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.

Saint John sits at the mouth of the Saint John river on the inner Bay of Fundy, on the Canadian east coast, where the largest tide range on Earth runs through the working harbour twice a day. The Bay of Fundy resonates close to the natural period of the lunar semidiurnal forcing, which means each tide reinforces the previous one as it propagates up the funnel-shaped basin, building amplitude on the way to the head where the geometry concentrates the entire mass of water into a narrow throat. Burntcoat Head Park across the bay on the Nova Scotia side holds the official Guinness world record for tidal range at 16.3 metres of swing on the largest spring tides; Saint John itself runs slightly less because it sits closer to the mouth of the bay than to the head. Mean range at the Saint John harbour gauge is about 6.9 metres on a normal day, climbing past 8.5 metres on the largest spring tides and dropping near 5.0 on neaps. The pattern is cleanly semidiurnal — two highs and two lows of comparable size each day, twelve and a half hours apart. The Reversing Falls at the mouth of the Saint John river is the defining local feature: the rising Bay of Fundy tide overpowers the river current at the harbour entrance and pushes water upstream into the river basin, then reverses direction as the tide drops, producing standing waves and a navigable slack window only at high and low water. Hopewell Rocks across the bay on the New Brunswick side, the Fundy Trail Parkway, the working fishing fleet at Saint Andrews on Passamaquoddy Bay, and the Salmon Cove sand beach at Quaco Head all read the table for different windows. The lowest spring lows expose mud flats stretching kilometres offshore and the bottom of the cycle reveals the upper half of the working pier pilings that the rising tide will cover entirely twelve hours later. Open-Meteo Marine drives the gridded predictions on this page; for authoritative Canadian Maritime tide data, the Canadian Hydrographic Service publishes the official tide tables and operates the Saint John reference gauge.