MDOUKHA, Lebanon — The winds spilling down off snow-covered Mount Hermon, bearing the first nip of winter, rattled the broken windows of an abandoned elementary school here where Syrian refugees are huddled in the Bekaa Valley hamlet.
Hundreds of thousands of Syrians displaced by the war, many of them stumbling out of Syria during the summer wearing little more than T-shirts and flip-flops, now face the onslaught of winter with inadequate shelter, senior government officials and aid organizations say.
‘‘It will be winter outside and winter inside,’’ said Mohamed Khair al-Oraiby, a 27-year-old who fled here over the summer with his wife and two infants. ‘‘We already wake up early because it is so cold.’’
With temperatures already plunging to zero overnight in the hills framing this valley, the humanitarian crisis facing millions of displaced Syrians is deepening. More than a million people in need of aid remain out of reach of international relief efforts, the United Nations says.
The inability of international aid groups to cope with the crisis has mushroomed. More than 400,000 people have fled Syria, and 1.2 million have been driven from their homes within the country, according to the UN refugee agency.
Some 2.5 million people need humanitarian assistance, and the number keeps climbing. The United Nations said it had reached only one million of them.
But efforts have also been hampered by lack of resources. The United Nations is seeking some $487 million for refugees across the region, of which about 35 percent has been collected.
“The capacity of the international donor community to support the crisis is not happening at the same speed at which the crisis is unfolding,’’ said Panos Moumtzis, the regional coordinator for the Office of the UN High Commissioner for Refugees.
Neighboring countries coping with the influx are developing their own plans: Jordan is seeking about $700 million, and Turkey, which has spent $400 million of its own money on state-of-the-art camps with three hot meals daily, is also now seeking aid.
Inside Syria, conditions are even worse. The distribution of aid is plagued by problems of access, security, and a lack of organizations to carry out the work, according to aid officials. Some areas have fallen under the sway of shadowy jihadist forces that eye Western aid organizations as espionage networks.
The Syrian government has allowed only eight foreign aid organizations to operate, and seven employees of the Syrian Red Crescent have been killed.
The largest aid donors are the United States, at $8.5 million, and Britain, at $7.8 million.
The wealthy Arab gulf states have contributed little via the UN system, with the exception of Kuwait, which has contributed $1 million.