The school at the Al Zaatari refugee camp in Mafraq, Jordan, was closed for three weeks after the heavy rain meant people in the refugee camp needed to use it as a base to take shelter.
The city of Mafraq is near to the border with Syria.
On January 11, the United Nations High Commissioner for Refugees said a total of 612,134 Syrians had already been registered or were in the process of being registered in neighbouring countries and in north Africa.
Meanwhile, Syrian opposition fighters captured a military airport near the northern city of Aleppo yesterday, an opposition organisation has said.
The airport is the latest military facility in the region between Syria's industrial and commercial centre and its oil and wheat producing heartland to the east to fall under rebel control.
The Jarrah air base, 28 miles east of Aleppo, came under the control of rebel units who have been surrounding it for weeks and the highway linking Aleppo to the east of the country is in opposition hands, the Sham News Network said.
Video footage showed fighters from the Islamic Free Sham Movement inspecting the airport.
Several fighter jets were shown on the ground at the airport and in concrete shelters. The video footage could not be independently verified.
One of the opposition commanders at the airport told journalists by phone two operational MiG jets and some ammunition were found intact at the base.
"The airport was being used to bomb northern and eastern rural Aleppo. By capturing it, we have cut the regime's supply line from Aleppo to the east," the commander said.
He said he thought the Syrian army would struggle to send re-inforcements to stop a rebel advance in the adjacent Raqqa province, where rebel fighters managed to capture the country's largest hydro-electric dam this week.