The figure is just 10 shy of the overall annual record from 2010, according to the nonprofit Humane Borders and the Pima County Medical Examiner's Office, which together map recoveries of human remains. This year saw extreme heat — a hallmark signal of human-caused climate change — across the American West. Phoenix, Arizona endured its hottest summer on record with 144 days in triple digits and an average daily temperature around 110°F throughout July and August.

Those months were also the state's driest on record. Trump's border wall also likely contributed to the uptick in deaths. "The wall has sent a lot of people to rough terrain in our area," Santa Cruz County Sheriff Tony Estrada, a critic of the president and advocate for greater compassion in immigration policy whose jurisdiction includes Nogales, Arizona, told The Associated Press. "It's like driving livestock into a canyon where they ultimately die."

As reported by The Associated Press:

In southern Arizona, No More Deaths and similar humanitarian groups leave water jugs and other provisions in remote places. The group gained national attention when one of its members was tried and acquitted last year of harboring migrants.

[Tony] Estrada, the Santa Cruz County sheriff, said he's worried officials may see higher numbers of deaths next year if big groups of migrants surge to the border, hoping Joe Biden's administration is more welcoming.

"These people will keep coming because most of them have nothing back home," Estrada said.