Meltemi in Greece: when it blows & islands to avoid in August

The meltemi is a dry, steady northerly wind that blows across the Aegean Sea from mid-May to the end of September, peaking in July and August. It typically reaches Force 4 to 6 on the Beaufort scale (Bft), or 11 to 27 knots, with gusts of Force 7 or 8 (28 to 40 knots). In August, the most exposed islands are in the Cyclades: Andros, Tinos, Mykonos, Naxos, Paros, Ios, Amorgos and Santorini. The Ionian Islands and the Saronic Gulf remain the most sheltered areas.

What is the meltemi?

The meltemi, also known as the etesian wind, is caused by the pressure difference between an area of high pressure over the Balkans and a thermal low over Turkey. Air flows from north to south across the Aegean.

• Direction: north-easterly in the northern Aegean, northerly in the Cyclades, north-westerly towards the Dodecanese and Crete.
• Associated weather: clear skies, dry air and less oppressive heat.
• Sea state: short, steep seas, especially in the straits between the islands.

When does the meltemi blow?

The meltemi follows a fairly predictable pattern:

• During the day: it picks up in the late morning, peaks in the afternoon and often eases in the evening.
• Length of an episode: usually 3 to 7 days, sometimes longer in high summer.
• Lulls: windows of 1 to 3 days of light wind often separate two episodes.

For boat hire in Greece in July or August, timing matters as much as where you sail: a lull of 1 to 3 days is often enough for an exposed crossing.

Which islands should you avoid in August?

The islands themselves are less of a problem than the crossings between them: the Kafireas Strait (between Evia and Andros), the passage between Mykonos and Tinos and the channel between Naxos and Paros are known for rough seas when the meltemi is in full force.

Where should you sail in Greece in August?

• Ionian Islands: the best choice in August, with a moderate thermal breeze in the afternoon and short distances. Boat hire in the Ionian Islands suits families or first-time crews: short legs, often under 15 nautical miles, and plenty of sheltered anchorages.
• Saronic Gulf: close to Athens, generally sheltered, with short island-hopping passages.
• Southern Dodecanese: moderate exposure and short legs between Nisyros, Tilos, Symi and Rhodes.
• Cyclades: best kept for experienced crews, or planned for June and September.

Filovent’s advisers will point you towards the most suitable departure base for your sailing dates and your crew’s experience.

How to sail in the meltemi

• Plan your route so the wind is behind you (downwind) rather than on the nose (upwind). Head south at the start of the week, then come back north in short, early-morning legs. If the base allows it, a one-way charter avoids the beat back.
• Set off early in the morning and arrive before the wind builds in the afternoon.
• Allow 1 to 2 spare days in your schedule in case you are stuck in port.
• Anchor on the south coasts of the islands, sheltered from the swell, while watching out for gusts funnelling down from the high ground on mountainous islands (Amorgos, Ios, Andros).
• Check the forecast every day, for example on the website of the National Observatory of Athens (meteo.gr) or the Hellenic National Meteorological Service (emy.gr).
• Opt for skippered boat hire if your crew lacks experience in strong winds.

Frequently asked questions about the meltemi

Is the meltemi dangerous?

It is not dangerous for an experienced crew on a well-prepared boat, but it makes sailing physically demanding and uncomfortable. Before skippering yourself, check the boat licence requirements in Greece and assess your ability in strong winds. In strong winds, the Greek port authorities may ban departures; the threshold depends on the type and size of the boat.

Catamaran or monohull in the meltemi?

A catamaran heels very little and is more comfortable at anchor, but it can’t point as high into the wind. A monohull performs better upwind in a heavy sea. Either way, your route matters more than the type of boat.

Can a meltemi episode be forecast?

Yes, usually 3 to 5 days in advance. Weather models and the Poseidon system run by the Greek institute HCMR (poseidon.hcmr.gr) predict its arrival and strength reliably, so you can adapt your route day by day.

Should you avoid the Cyclades in summer?

Not necessarily. June and September are the best months to sail there. In July and August, departing from Lavrio or Athens, favour Kea, Kythnos and Syros, which are less exposed than Mykonos or Naxos, and save long crossings for calmer days.