McALLEN, Texas (Border Report) — In the past two days, U.S. Border Patrol agents in the Rio Grande Valley have come across over 500 undocumented migrants in three large groups in deep South Texas, despite temperatures in the high 90s, U.S. Customs and Border Patrol reported Thursday.

In 48 hours, agents encountered 512 migrants in Starr and Hidalgo counties. This included 146 unaccompanied migrant children and 276 family members from Cuba, Central and South America, according to CBP.

Large groups are considered groups of migrants that include 100 people or more and are usually found in rural border towns just north of the Rio Grande.

CBP said in a statement that the logistics required to transport and process large groups “continue to place a strain on manpower and resources, as often they are encountered in desolate areas often inaccessible to large transport vehicles.”

Despite Title 42 still being in effect, migrants continue to try to cross the border from Mexico into Texas.

CBP reports that May encounters of migrants reached an all-time monthly high. Nationwide, border authorities encountered migrants 273,309 times in May, representing a 4 percent increase from the 261,780 migrant encounters in April. March and April were both record-setting months for migrant encounters.

CBP officials warn migrants not to make the dangerous journey north, especially in the intense summer heat.

“As temperatures start to rise in the summer, human smugglers will continue to exploit vulnerable populations and recklessly endanger the lives of migrants for financial gain. The terrain along the Southwest Border is extreme, the summer heat is severe, and the miles of desert that migrants must hike after crossing the border are unforgiving. Our message to those who would try and gain illegal entry to the United States remains the same – don’t make the dangerous journey only to be sent back,” CBP Commissioner Chris Magnus said in a statement.

The number of CBP search and rescue efforts for Fiscal Year 2022 have already far eclipsed year totals for recent years. So far, there have been 14,278 rescue and search efforts this fiscal year; which exceeds the 12,833 efforts in all of Fiscal 2021, according to newly released CBP data.