How We Read the Marine Forecast Before Setting Off in Mallorca

Which sources are consulted

The official reference in Spain is the State Meteorological Agency (AEMET), which publishes marine forecasts for coastal and high-seas waters; for the Balearics, the coastal area is called «Costa de Illes Balears». Warnings are issued with a 48-hour horizon, text forecasts cover 24 hours and maps run up to 5 days.

Besides AEMET, other sources add complementary data: Puertos del Estado, with buoys that measure waves in real time, the SOCIB coastal observing system, specific to the islands, and freely available weather models such as Windy or Windguru, which show wind hour by hour. No single source is enough: the professional approach is to cross-check them.

The scales: Beaufort and Douglas

Wind is expressed on the Beaufort scale, from 0 to 12. As a reference, force 4 (moderate breeze) corresponds to about 11–16 knots, force 5 (fresh breeze) to 17–21 knots and force 6 (strong breeze) to 22–27 knots. From force 5 sailing starts to become uncomfortable on pleasure craft.

Sea state is described with the Douglas scale, from 0 to 9, whose terms appear in the forecasts: calm, smooth, slight, moderate, rough… For a day of swimming and lunch on board, comfortable conditions are usually around a calm-to-smooth sea and light to moderate wind.

Mallorca's winds and how they affect each coast

The winds have names of their own: tramuntana (north), gregal (northeast), llevant (east), xaloc (southeast), migjorn (south), llebeig (southwest), ponent (west) and mestral (northwest). What matters is how they interact with the coast: the Serra de Tramuntana acts as a barrier and shelters Palma and much of the bay from the tramuntana and mestral, while Cap de Formentor, the Bay of Alcúdia or Cap de Capdepera can be very exposed on the same day.

The llevant hits the east coast head-on, with more swell than in the western or southern bays; the migjorn and xaloc mainly affect coves open to the south and southeast. That is why the choice of port and sailing area matters; read more in our guide to which port to choose in Mallorca.

How the decision to sail is made

The decision doesn't rest on a single figure. You look at the wind trend through the day, direction relative to the coast (with an offshore wind there is more shelter near the shore and more sea further out), any ground swell arriving and the likelihood of storms, more frequent in late summer and autumn. Visibility counts too.

The criterion is always conservative: if the safety margin isn't clear, the plan is rethought. The final decision rests with the skipper, who is responsible for the safety of the boat and the people aboard.

Plan B: alternatives and flexibility

A good day at sea usually includes an alternative: if the wind picks up in the planned area, you change cove, coast or timing. That's why it pays to be flexible with the itinerary and to confirm the departure the same morning with an updated forecast. We cover this, with more seasonal context, in our guide to the best time to sail in Mallorca.

A reading example, step by step

Imagine a forecast announcing northeast wind of 10 to 15 knots in the morning, veering southwest in the afternoon, with a calm-to-smooth sea. The professional reading would be: in the morning, with an offshore wind along much of the south and west coast, there will be shelter near the shore; in the afternoon, as the wind veers, some coves will become more exposed. The practical conclusion would be to anchor early in a cove sheltered from the northeast and plan the return before the wind settles in from the southwest.

What matters is the logic: you don't read a number, you read the evolution of the day, the direction relative to each coast and the effect on the plan.

Mean wind, gusts and swell

Forecasts usually give the mean wind, but gusts can be considerably higher, especially near headlands, in areas with relief and on unstable days. That's why the gust value is always checked, not just the mean.

It is also worth distinguishing between wind sea, generated by the local wind, and swell, which arrives from distant storms and can be felt even in light wind. A long-period swell is comfortable; a short-period one is uncomfortable even if the wave height is moderate.

Storms and autumn

In late summer and autumn, intense storms and rapid changes are more frequent. Faced with such forecasts, the rule is simple: you don't go out with a storm forecast within the sailing window, and you follow the evolution with radar and warnings until the last moment. Prudence in those weeks isn't excess caution; it's the standard of the craft.

Sources

AEMET, marine forecast · Puertos del Estado · SOCIB. Checked in September 2026.

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