According to the UNHCR, more than 3.8 million refugees and internally displaced people in Syria, Lebanon, Iraq, Turkey, Jordan and Egypt need winter assistance.
A cold weather programme which began last month is aimed at helping the most vulnerable families.
But of the $228m needed to finance this year's winter programme, only $143m has been received - a shortfall of nearly 40 percent.
Al Jazeera's Imtiaz Tyab reports.