King tides are a fascinating natural phenomenon that attracts many curious people to the French and European coasts every year. In 2025, these spectacular tides will occur several times, offering special moments to watch the sea retreat into the distance or rise to its highest level. Discover the key dates, read our article to better understand the phenomenon and enjoy these exceptional events safely.
Anticipate and plan your activities, aim for the right moment…
Dates of King tides 2025
The dates of the King tides 2025 are yellow in the table.
In the first part of the year 2025, the King tides occur at the time of the new moon. In the second part of the year, they occur at the time of the full moon.
These dates are valid for the English, French, Spanish or Portuguese coasts. These times occur at the same time on this entire coastline.
This table is also a lunar calendar, you will find the phases of the moon 2025 valid for Europe.
What is a King tide ?
A King tide is a natural phenomenon, a period during which the sea rises and falls dramatically (more than usual), with a significant difference between high tide and low tide. The tidal ranges* are the largest of the year.
At any point along the coastline mentioned above, the movement of the water is greater than during other periods.
Remember that SHOM, the French hydrographic services, by convention, defines the period of spring tides when the tidal coefficient is equal to or greater than 100.
Elsewhere in Anglo-Saxon countries they are called “Spring Tides” and “King Tides” when they are exceptional. Royal tides!
When do the King tides occur?
They occur when the moon, sun and earth are aligned during full moons and new moons.
This position of the stars amplifies the gravitational attraction exerted on the oceans.
Twice a month it is a period of spring tides at the tide level.
The sun comes to boost the action of the moon on the oceans which attracts the mass of water and pushes it back with more force. These periods of spring tides are sometimes even stronger with a tidal coefficient greater than or equal to 100 = King tides.
Twice a year the spring tides are necessarily there during the spring equinox and the autumn equinox. The sun passes at the equinoxes on the plane of the equator, its action is therefore stronger on the masses of water.
Reminder on how the tides work
The phenomenon of tides arises from celestial mechanics, the movement of the 3 stars: earth, moon and sun.
The moon is the main driver of the tides.
So depending on the rotation of the earth and the positioning of the moon, the masses of water move.
There are several tidal zones with their own times and water heights. 1 tidal zone = 1 tidal calendar.
To learn more, watch Béatrice’s video.
Tides are astronomical and are predicted well in advance like the movement of the stars.
The dates of the King tides are also predicted.
It is often necessary on the coast to consult a tidal calendar before planning an activity related to the sea.
What is the relationship between tidal coefficients and king tides?
As a reminder, the tidal coefficient in France allows you to clearly and quickly know the importance of the water heights.
The greater the tidal range, the greater the coefficient.
This is a figure between 20 and 120, which means that the tide on the French coast varies in a proportion of 1 to 6.
It is calculated for the main port of Brest as a reference. This coefficient is valid and representative across the entire coastline.
Of course, each tidal zone has its own times and water heights, but the proportion of the tidal range is the same, so the coefficient works for all tidal zones in France (and even in Europe in the Atlantic, the Channel and the south of the North Sea).
This notion of tidal coefficient is only used in France by our hydrographic services. The latter have decided that we could use the term “King tides” from coefficient 100 and above.
King tides, a beautiful spectacle
This is the time when the foreshore is most exposed all over the coast. The sea retreats for several kilometers, revealing stretches of sand, rocks and ideal areas for fishing. Some places are exceptionally accessible.
It’s up to you to take advantage of it for fishing on foot, sand yachting, cycling on the beach, horse riding, going around a rock that is normally inaccessible, visiting wrecks in Normandy… Everyone has their own activity.
This is also the time when the waters rise to cover more land than usual.
The waves hit the dikes and sometimes completely surround emblematic sites like Mont-Saint-Michel or Bristol estuary.
Tips for enjoying the king tides of 2025
Check the precise tide times for your area to arrive at the right time.
The ideal is often to arrive one hour before high tide or low tide.
Choose the right spot that is most emblematic of your coastline:
* In France: Mont-Saint-Michel, Saint-Malo, Baie de Somme. The most significant tidal ranges on the French coast.
But in any geographical area, the importance of the tidal range is magnified.
* In Spain, aim for the beaches of Galicia.
* In Portugal, head to the Algarve Coast.
* In England, the spots are on the beaches of Devon and Cornwall. The most impressive tidal range is around the Bristol Estuary, comparable to Mont Saint-Michel Bay.
* The place in the world where the tidal range is the most significant is located in Canada on the Atlantic coast in Nova Scotia in the Bay of Fundy.
Safety first
* Do not venture alone onto the foreshore (open area at low tide). Be careful not to get trapped by the rapid rise in water levels.
* Check weather conditions, as strong swells can make observation dangerous.
* Follow local recommendations.
The importance of weather during high tides
Depending on the weather conditions, King tides can be dangerous.
The magnificent spectacle can also cause damage.
The cocktail of swell, low atmospheric pressure, coefficient above 100 and strong gusts can lead to flooding or even submersion waves.
This is the worst-case scenario on the coast. Let’s take the recent example of the Karlotta depression in February 2024, very strong winds, rough seas and heavy rain. In fact, this collusion of elements can lead to a sharp rise in water levels and submersion waves. There can be an “overshoot” of several centimeters compared to the height forecasts. The rivers at the level of the estuaries can overflow at worst.
All the King tides at a glance on our Tidal Calendar
Plan your King tides, check the precise tide times to arrive at the right time and visualize a whole year thanks to our tide calendar displayed in your interior.
Discover our tidal calendar in large format 60 x 80 cm and 50 x 70 cm printed directly on wood and in paper posters.
Available for the entire French west coast, some places in England, Spain, Portugal and Germany.
Customization of your tide zone and the title of the useful and decorative calendar format!
- tidal range: difference in water height between 2 consecutive tides, high and low.
