Most Greek charters take place between May and October, and in the Aegean the wind shapes the plan as much as the heat. The meltemi, a dry northerly, blows from about mid-May to mid-September, peaking in July and August, and is strongest in the Cyclades. It can reach force 6 or more for days at a time, so captains sail in the calmer early morning, run south with the wind behind them and anchor on the sheltered southern side of the islands. The Ionian Sea and the Saronic Gulf are calmer in high summer.

APRIL AND MAY

19–25°C

Best for ruins, wild flowers and empty quays

Spring is the season for walking, wild flowers and archaeological sites. Hillsides are green, harbours are half empty and the air is warm but not yet hot, while the sea, at around 17–20°C, is bracing rather than balmy. Greek Orthodox Easter, which falls in April or early May, is the biggest festival of the year, with candlelit processions and fireworks at midnight.

JUNE

26–30°C

Best for long evenings and a lighter meltemi

In June the sun sets late, dinners on deck run long, and the water off the islands reaches about 21–23°C. The meltemi is usually lighter and less frequent than it will be in high summer, and the Greek holiday rush is still weeks away, so the Ionian, the Cyclades and the Dodecanese are all at their best.

JULY AND AUGUST

28–33°C

Best for hot days and the liveliest islands

High summer brings the year’s peak heat, the most yachts on the water and sea temperatures of around 24–26°C. The meltemi is at its strongest, so routes in the Cyclades are planned around it, while the Ionian and the Saronic Gulf are calmer. August is when Greece itself goes on holiday, and around the feast of the Dormition on 15 August ferries are full and popular harbours and anchorages fill early in the day. Reserve your dates well in advance.

SEPTEMBER

26–29°C

Best for warm water after the crowds leave

After a whole summer of sun the water holds its warmth, at around 24–25°C, while the islands empty noticeably once Greek schools go back. The meltemi eases as the month goes on, and Spetses celebrates the Armata, marking the anniversary of its naval battle of 1822. Warm water, quieter quays and softer light make it hard to beat.

OCTOBER

22–26°C

Best for soft light and quiet islands

Swimming carries on through October, with the sea at around 21–23°C, and the season lingers longest in the Dodecanese and the southern Aegean. Expect the odd unsettled day and earlier sunsets. Some tavernas and beach bars shut for the winter as the month goes on, and part of the charter fleet heads for its winter berths, so it pays to reserve October weeks early.