The best time to visit Marathon, Attica, Greece, for pleasant weather and fewer crowds is during the shoulder seasons of May, early June, September, and early October.During these months, the weather is comfortably warm but not excessively hot, with average temperatures ranging from 20°C to 28°C. This makes it ideal for exploring the historical sites like the Marathon Tomb and the Marathon Archaeological Museum without the intense heat of mid-summer. It's also superb for enjoying the beaches along the coast, such as Schinias Beach, before they get too busy.For those prioritising a quieter experience and cooler temperatures, late April or late October can also be appealing. The sea might be a bit cooler for swimming, but you'll find the archaeological sites and natural areas even more peaceful, and accommodation prices can be more favourable.