The number of migrants and refugees entering Europe by sea last month was roughly the same as that for the whole of 2014, United Nations refugee agency UNHCR said on Monday.
The monthly record of 218,394 also outstripped September's 172,843, UNHCR spokesman Adrian Edwards said.
"That makes it the highest total for any month to date and roughly the same as the entire total for 2014," he said. The UNHCR puts 2014 arrivals by sea at about 219,000.
At the peak, 10,006 arrived in Greece's shores on a single day, Oct. 20. The vast majority of refugees and migrants to Europe have traveled via Turkey to Greece, a switch from the previously more popular African route via Libya to Italy.
The largest group by nationality are Syrians, accounting for 53 percent of arrivals, as a result of the civil war that has driven hundreds of thousands from their homes. Afghans come second, making up 18 percent of the total.
The flow of refugees into Europe, however, is still dwarfed by the numbers in Syria's neighbors. Turkey, Lebanon and Jordan have Syrian refugee numbers exceeding 2 million, 1 million and 600,000 respectively.
Globally, 60 million people are refugees or displaced within their own country, not counting economic migrants.
UNHCR said in October that it was planning for up to 700,000 refugees in Europe this year and a similar or greater number in 2016.
But that plan has already been eclipsed, with 744,000 arriving so far. Some 3,440 are estimated to have died or gone missing in the attempt to escape to Europe.
"Certainly in 2016, we have to expect this level of arrivals to continue, and that's because the facts that are causing people to move aren't going away," said Edwards.
"It is the new reality that we all have to deal with."
Migration experts had expected the number of people making the hazardous journey by sea to dwindle as winter approached, but the boats have continued to arrive.
"We hope that there will be some reductions in the number of people crossing this year, simply to help with the manageability of the situation, but unfortunately, the underlying causes that are making people move across the Mediterranean to Europe are still there," Edwards said.
The Greek coast guard said on Monday that four refugees drowned and another six were missing off the Greek island of Farmakonisi after their boat sank.
Four people were rescued. Eleven people, including six infants, drowned on Sunday when their boat capsized off the island of Samos, trapping them in the cabin.
(Reporting by Tom Miles and Marina Depetris; Editing by Tom Heneghan)