Update January 29, 2024: CBP has released final December 2023 data. Read an updated post with nine charts illustrating migration trends.

Border Patrol shares monthly data about its apprehensions of migrants at the U.S.-Mexico border since October 1999. As this chart shows, during that time, the number of migrant apprehensions in a single month has never exceeded 225,000. (224,370 in May 2022, 222,018 in December 2022, 220,063 in March 2000.)

Data table

That threshold has now been passed. CBS News’s Camilo Montoya-Galvez reported yesterday, “U.S. Border Patrol agents took into custody more than 225,000 migrants who crossed the southern border—in between official crossings—during the first 27 days of December, according to the preliminary Department of Homeland Security [DHS] statistics.”

(This number does not include approximately 50,000 more migrants who come each month to ports of entry—official border crossings—usually with appointments.)

Montoya-Galvez shared Border Patrol’s daily averages, showing modest decline in migrant arrivals over the past week:

The current spike in migration peaked before Christmas, during the week starting on Dec. 14 and ending on Dec. 20, when Border Patrol averaged 9,773 daily apprehensions, according to the data. On several days that week, the agency processed more than 10,000 migrants in 24 hours.

Unlawful crossings along the U.S.-Mexico border have decreased this week, but remain at historically high levels. On Wednesday, Border Patrol processed 7,759 migrants, the statistics show.

In his morning press conference yesterday, Mexican President Andrés Manuel López Obrador shared this slide of data from Customs and Border Protection (CBP, Border Patrol’s parent agency), depicting CBP’s monthly migrant encounters through the first 17 days of December. This slide appears to combine Border Patrol apprehensions with CBP’s port-of-entry encounters, so the numbers are a bit higher.

Combining encounters with migrants at the ports of entry and between them, the chart shows a daily average of 9,787 people per day over December 1-17, increasing to 10,187 per day over December 1-21.

The chart shows a sharp increase in daily arrivals of Venezuelan citizens, whose numbers dropped in October and November after the Biden administration’s October 5 announcement that it was resuming deportation flights to Caracas.

There have since been 11 such flights, DHS reported on December 27. It appears that despite the (not huge) risk of being on one of these roughly one-per-week flights, Venezuelan asylum seekers are again coming in greater numbers.