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 01:00 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.

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

Next spring tide on Fri 01 May (range 1.6m). Next neap on Tue 28 Apr.

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.

Tokyo Bay opens south through the narrow Uraga Channel between Yokosuka and the Bōsō Peninsula, a 7-kilometre throat where the open Pacific reaches in to fill a partially-enclosed basin ringed by Tokyo, Yokohama, Kawasaki, and Chiba. The tide signature here is a moderate mixed-semidiurnal signal — two highs and two lows of unequal size each day, the bigger swing falling on the lower-low water — with the pattern shifting toward strongly diurnal at certain points in the lunar month. Mean range at the Harumi gauge in central Tokyo is about 1.3 metres, climbing past 2.0 metres on the largest spring tides and dropping near 0.6 on neaps. That is modest compared with the Pacific Northwest US or the European North Sea, but the bay's geometry concentrates currents through the Uraga Channel to over two knots on the change of tide, which the working pilots on the deep-water container approaches at Yokohama and the Tokyo-Bay ferry skippers reading for Kanazawa-Hakkei and Kisarazu both notice. The wholesale fish market at Toyosu (which moved from Tsukiji in 2018) timed its working hours around the Edomae inshore fishing fleet for centuries, and the rhythm survives in the tsukudani salt-cooked seafood that originated on the bay shore. Sailors out of Yokosuka and the Miura Peninsula reading for the open Sagami Bay, surfers at Kujūkuri on the Bōsō outer coast, and shellfish harvesters at the few remaining tidal flats around Funabashi each read the table for different windows. Open-Meteo Marine drives the gridded predictions on this page; for authoritative Japanese tide data, the Japan Meteorological Agency and the Japan Coast Guard Hydrographic and Oceanographic Department publish the official tide tables and operate the Harumi reference gauge.