The influx stems from an increase in migration from Central America, Haitian nationals from Brazil and Cuban nationals, according to U.S. Customs and Border Protection (CBP). There has also been an increase in the number of people seeking asylum at the border.
The total number is up over 100 percent from last year for the months of October and November.
By another measure, the total number of family units and children apprehended on the southwest border during those first two months of fiscal year 2017 was one-third of the entire number of apprehensions for all of last year.
The largest number, year-to-date, of unaccompanied children came from Guatemala, followed closely by El Salvador and then Honduras, officials said.
Two years ago, the surge of unaccompanied minors put extreme pressure on the facilities, resources, and capabilities of CBP and other federal agencies.
During 2014, unaccompanied children peaked at 10,578 and 10,620 for May and June, respectively, which was during the warm-weather months, when border crossings typically increase. They generally begin to go down into the winter months.
Last month, 7,406 children were apprehended, up 10 percent from October.
In November, there were 15,573 family units apprehended. Family units saw a peak of 16,330 in June 2014. May was next highest with 12,772 families being apprehended. Apprehensions are used as an indicator of the total number of attempts to cross the border illegally.
In response to the recent surge, CBP opened two temporary tented facilities in Texas, each capable of holding up to 500 people.
In addition, Border Patrol, which is run by CBP, temporarily deployed 150 agents to the Rio Grande Valley, which is far and away the most affected region on the border. It consistently has the most apprehensions of any Border Patrol sector.