NBC baffled: Despite climate change, illegals still pouring across border

While Texas Gov. Greg Abbott places buoys in the Rio Grande to make it harder for migrants to cross into his state, a growing number of migrants have braved record-breaking heat and dangerous terrain to cross into Arizona.

Long considered the most dangerous area to cross the U.S.-Mexico border, the Tucson sector is now also its busiest. On average, more than 1,300 migrants cross daily despite temperatures that regularly top 100 degrees, according to Customs and Border Protection data obtained by NBC News.

“This is a very rough, rough entrance into the United States,” said Jim Chilton, a rancher in Arivaca, Arizona, who regularly sees migrants cross his 50,000 acres of land.

“It’s gotten worse,” he said, noting a seemingly undeterred migrant population traversing his ranch.