Matsushima tide times

Mean tidal range at Matsushima is approximately 1.3 metres above MLLW. The bay's semidiurnal pattern produces two highs and two lows each day, with timing shifting roughly 50 minutes later each day. At high water, the smallest islands shrink to rock outcrops barely clearing the surface; at low water, the inter-island shallows and sand channels open and the lower half of each island's rock face is exposed. Spring tides (within 2 days of new or full moon) can push high water up to roughly 0.3 metres above the mean high water level. Knowing the tide state before visiting the bay is worth the 30 seconds it takes — the scene at low water and high water are genuinely different experiences.

Matsushima-gaki (Matsushima oysters) are in season from October through March. The aquaculture ropes are visible in the bay from late summer onward; harvesting happens through the cooler months when the water temperature keeps the oysters in peak condition. The waterfront town has multiple restaurants and stalls — grilled (yakigaki) over charcoal with a squeeze of lemon is the local standard. Outside the October–March window, oysters may still be available but the season stock is gone. The annual Matsushima Oyster Festival runs in late February at the waterfront, with grilled oysters sold by the kilo direct from local producers.

This is an important distinction. The tide predictions on this page show astronomical tides — the regular, predictable rise and fall of sea level driven by the gravitational pull of the moon and sun. These are forecastable days and months in advance. Tsunamis are entirely different. They are generated by sudden seafloor displacement — earthquakes, submarine landslides, or volcanic events — and have no relationship to the tidal cycle. They cannot be predicted by any tide chart. The 2011 Tōhoku earthquake (magnitude 9.1, epicentre approximately 70 km east of the Oshika Peninsula) generated a tsunami that reached heights of 10 to 40 metres above MLLW along the Sanriku coast north of Matsushima. Nearly 20,000 people died. Matsushima Bay's island geography provided some attenuation, but the event reshaped the entire regional coastline. The Japan Meteorological Agency (JMA) operates Japan's tsunami warning system — entirely separate from tidal prediction. JMA issues tsunami advisories within approximately 3 minutes of a significant earthquake. In Miyagi Prefecture, follow JMA alerts, local sirens, and the instructions of local authorities. When an earthquake is felt strongly near the coast, do not wait for a formal warning before moving to higher ground.

Godaidō is a small wooden hall (1604) built on a tiny islet 50 metres from the Matsushima waterfront, connected to shore by two arched wooden bridges. It is one of the oldest wooden structures in the Tohoku region and a national cultural property. The hall houses five Buddhist images that are displayed only once every 33 years — the next display is due in 2039. At all times the exterior is accessible; the building's position on the islet, framed by the surrounding islands, makes it the most-photographed element of Matsushima. It is accessible at any state of tide via the bridges.

No. Predictions here come from Open-Meteo Marine, a gridded global ocean model that estimates tide heights and timing from astronomical inputs. Accuracy is typically within plus or minus 45 minutes on timing and 0.2 to 0.3 metres on height relative to observed levels. For safety-critical decisions — navigation, commercial fishing, construction near the water — use the Japan Meteorological Agency's official tide tables at jma.go.jp. The JMA operates the authoritative tide gauge network and publishes verified predictions for reference stations along the Tohoku coast. This page is a planning and reference tool, not a substitute for official data.