A monthly record of 218,394 migrants and refugees arrived in Europe by sea in October, says Adrian Edwards, a spokesman for United Nations refugee agency UNHCR.
â€œThat makes it the highest total for any month to date and roughly the same as the entire total for 2014,â€ he said.
The UNHCR puts 2014 arrivals by sea at about 219,000.
Last week, the Greek coastguard rescued 242 migrants when their wooden boat sank north of the island of Lesbos, but at least three drowned in the same incident.
More than 500,000 refugees and migrants have entered GreeceÂ through its islands since January, transiting on to central and northern Europe in what has become the biggest humanitarian crisis on the continent in decades.
In September, the image of the Syrian toddler Aylan Kurdi washed up on a Turkish beach sparked global debate on the refugee crisis sweeping Europe, with pressure mounting on leaders to develop a coherent response to prevent further deaths.