Autos drive by the snow-coverd forest of Berlin's Tiergarten Park, in Berlin, Germany, on Dec. 29, 2014. Winter weather hit Germany's capital city of Berlin as the temperature dropped to minus four degrees centigrade on Monday. (Xinhua/Zhang Fan)

A woman walks through a coffee shop as snow-coverd tables and chairs are reflected on the window near Berlin's Tiergarten Park, in Berlin, Germany, on Dec. 29, 2014. Winter weather hit Germany's capital city of Berlin as the temperature dropped to minus four degrees centigrade on Monday. (Xinhua/Zhang Fan)

People walk through the snow-coverd forest at Berlin's Tiergarten Park, in Berlin, Germany, on Dec. 29, 2014. Winter weather hit Germany's capital city of Berlin as the temperature dropped to minus four degrees centigrade on Monday. (Xinhua/Zhang Fan)

People walk through the snow-coverd forest at Berlin's Tiergarten Park, in Berlin, Germany, on Dec. 29, 2014. Winter weather hit Germany's capital city of Berlin as the temperature dropped to minus four degrees centigrade on Monday. (Xinhua/Zhang Fan)

A man takes photos as his children plays on the snow-coverd ground near Berlin's Tiergarten Park, in Berlin, Germany, on Dec. 29, 2014. Winter weather hit Germany's capital city of Berlin as the temperature dropped to minus four degrees centigrade on Monday. (Xinhua/Zhang Fan)

People walk through the snow-coverd forest at Berlin's Tiergarten Park, in Berlin, Germany, on Dec. 29, 2014. Winter weather hit Germany's capital city of Berlin as the temperature dropped to minus four degrees centigrade on Monday. (Xinhua/Zhang Fan)