Milos is a summer island, and the best time to visit depends on what you want from the sea, the crowds and the weather. The short answer for most travellers is June or September, when the sea is warm, the days are long or pleasantly mild and the island is less crowded than in midsummer. The longer answer involves the wind.
The meltemi
In July and August the Aegean is dominated by the meltemi, a strong, dry north wind. It clears the sky and tempers the heat, but it also raises waves, makes some beaches rough and can cancel or reroute boat trips. The south coast is often sheltered, so many visitors switch sides of the island depending on the forecast. It is not constant, and calm spells occur, but it is the main variable for a summer stay.
June
Many visitors consider June the best month: days are long, there is little wind, the island is green-brown rather than parched, prices are lower than in peak season and most boats, tavernas and hotels are open. The sea is slightly cooler than in late summer but clear. It is excellent for boat trips and hiking.
July and August
The hottest, busiest and most expensive months. Beaches and car parks fill early, tavernas and ferries sell out and accommodation is at its dearest. The atmosphere is lively, and everything is open, including water sports and sunset cruises. Reserve everything early, start days early to beat the heat and the crowds, and be flexible with sea plans because of the wind. August in particular is crowded and difficult for last-minute accommodation.
September
The sea is at its warmest after a summer of heating, the wind often eases, crowds thin and prices drop. Days are a little shorter, and a late meltemi can still blow. For swimming, boat trips and a relaxed pace, many people prefer September to June. Some businesses begin to close toward the end of the month.
October
Often still sunny and pleasant, with fewer visitors, though the sea is cooler and some tavernas, hotels and boat operators wind down. Ferries run to a reduced timetable. It suits travellers who want quiet, walking and sightseeing more than long swims. Weather can turn overcast, so keep plans flexible.
Winter
From roughly November to March, the island is quiet and many hotels, restaurants and tours close. Ferries and flights continue on reduced schedules, and weather can be windy and wet, with rough seas that disrupt crossings. It is a time for locals and for travellers who want an off-season experience, but you will not have beach days, and boat trips do not operate.
Spring
April and May are green and mild, with wildflowers and few crowds. The sea is cool for swimming but fine for walking, culture and photography. Services increase through May, with more places opening as the season starts. It is a good time for history, hiking and the quiet fishing villages.
What is open when
The core season for boat trips, beach bars and full services runs from late spring to early autumn. Archaeological sites and museums follow seasonal hours, with shorter hours in winter and weekly closing days, so check with the Tourist Office. Hotels vary: some stay open all year, others close for the winter.
Food and drink through the year
Summer brings the full range of tavernas, beach bars and seafood restaurants, with long evenings and busy tables. In the shoulder months, restaurants are quieter and often easier to book, and the weather is pleasant for sitting outside. Local specialities include fresh fish, cheese pies, chickpea dishes and local cheeses. Reserve ahead in July and August, and ask about opening days outside the main season.
How to decide
If swimming and boats are your priority, choose June or September. If you like heat and a lively mood and can pay peak prices, choose July or August, but plan around the wind. If you prefer quiet, culture and lower prices, choose May or October. If you are flexible with dates, check the wind forecast, reserve boat trips early in the stay and keep a spare day.
A note on daylight and heat
In midsummer, afternoons are strong and shade is scarce, so plan sightseeing for the morning and late afternoon and keep the middle of the day for swimming, a long lunch or a museum. In spring and autumn, you can walk and explore comfortably all day, but carry a light jacket for the evening.