More than 3,000 refugees and migrants arrived at Piraeus by ferry from Lesvos and Chios on Monday.
The Ariadne carried 1,598 people, while 1,459 were on board the Tera Jet. Authorities said that another 1,206 people are waiting to travel from Lesvos on Monday.
Officials on the eastern Aegean island said the flow of refugees arriving from Turkey picked up on Sunday following a brief lull, possibly caused by some bad weather.
Almost 730,000 refugees and migrants have arrived in Greece by sea this year, according to the UNHCR. More than 425,000 have reached Lesvos, which has received by far the most people.