Korea High & Low Tide Times

Last updated: 2026-06-25

TL;DR

Tides follow a roughly 12-hour-25-minute cycle, giving two high waters (flood) and two low waters (ebb) per day. Pick a region and date to estimate the times as high water ≈ lunar transit + regional high-water interval.

These are approximate reference values. For exact times, always check the Korea Hydrographic and Oceanographic Agency (KHOA) tide forecast.

Pick region & date

Pick a nearby region. The regional high-water interval is applied.
Pick the date you want tides for. The default is today.

These are approximate estimates. For exact high/low water times and tide levels, always check the Korea Hydrographic and Oceanographic Agency (KHOA) tide forecast.

How to use

  1. Pick a region — Select a nearby region such as Incheon, Pyeongtaek, Gunsan, Mokpo, Busan or Jeju.
  2. Pick a date — Choose the solar date you want tides for. The default is today.
  3. Read the result — Approximate high and low water times and the tide are shown in a table. If a KHOA API key is set, observed forecasts replace the estimate.

How the estimate works and the regional correction table

Seawater rises and falls twice a day on a roughly 12-hour-25-minute cycle (semidiurnal tide) under the gravity of the moon and sun. High water occurs some time after the moon transits (crosses the meridian) at that location; this delay is the high-water interval. This tool approximates high water ≈ lunar transit + regional high-water interval, and estimates low water a half-cycle (about 6 hours 12 minutes) later.

Regional high-water interval (approximate correction constant)
RegionAreaHigh-water interval (approx. min)Mean range trend
IncheonCentral West Sea~540Very large (7-9 m)
PyeongtaekCentral West Sea~555Very large
GunsanSouthern West Sea~480Large
MokpoSouthwest Sea~420Medium-large
YeosuWestern South Sea~450Medium
BusanEastern South Sea~600Small (1-2 m)
UlsanSoutheast Sea~615Small
PohangSouthern East Sea~630Very small
SokchoCentral East Sea~645Very small (~0.3 m)
JejuJeju~510Medium

The East Sea has a very small tidal range, so highs and lows are not sharply distinguished. The intervals above are approximate correction constants and may differ from observed values. See the tide flow in the tide calculator and tide calendar, and seasonal fish in the fishing info hub.

Frequently asked questions (FAQ)

Are these high/low water times accurate?

No. The high and low water times here are approximate estimates from the lunar transit time plus a regional high-water-interval correction. Real tides are strongly affected by terrain and weather, so always check the Korea Hydrographic and Oceanographic Agency (KHOA) tide forecast for exact times.

How does the estimate work?

Tides follow a semidiurnal cycle (about 12 hours 25 minutes), giving two highs and two lows a day. High water is approximated as 'lunar transit + regional high-water interval', and low water is estimated a half-cycle later. Regional high-water intervals use a built-in correction table.

How do I connect the KHOA API?

Get an auth key from the KHOA Badanuri Ocean Information OpenAPI and put it in the page's KHOA_KEY value to call station-based tide forecasts instead of the estimate. If the key is empty, it automatically falls back to the estimate and shows a notice.

Why do high/low water times change every day?

Because of the moon's orbit, the lunar transit time gets about 50 minutes later each day. So high and low water times also shift about 50 minutes later each day. The tide phase (spring/neap) also changes with the moon's phase.

Last updated: 2026-06-25