Migrants queue on a bridge crossing the border river Inn at the German-Austrian frontier between Braunau and Simbach am Inn near Passau, Germany November 1, 2015. REUTERS/Michael Dalder

BERLIN (Reuters) - The number of refugees arriving in Germany in December has more than halved from the previous month, according to statistics from the German federal police obtained by Reuters on Monday.

The decline is probably due to bad weather in the Aegean Sea, the main crossing point for migrants to Europe, as well as tougher controls at Turkey’s external borders.

With its relatively liberal asylum rules and generous social benefits, Germany has become a magnet for migrants fleeing to Europe from war and deprivation in the Middle East, Africa and Asia. It expects to have taken in about one million this year.

From the start of the month until Dec. 20 some 73,500 migrants arrived in Germany, down from 170,000 in the same period in November, the police statistics showed.

Of the new arrivals, around 6,000 were traveling through Germany on their way to Scandinavia, bringing the net number of newcomers to some 68,000, police added.

The police statistics are based on sample checks in border areas. The number of new arrivals varied between 2,000 and 5,000 per day in December.

Data from Germany’s ‘Easy’ system, which is used for the initial registration of migrants and refugees, showed 965,000 migrants had arrived in Germany in 2015 by the end of November. This means the one million figure has probably been surpassed.

Many local authorities are struggling to cope with the influx and some members of Chancellor Angela Merkel’s conservatives have called for a cap on the number of new arrivals, a measure she has so far resisted.