Some 882 people were detected crossing the English Channel on Tuesday, the Home Office has said.
It is the highest number on a single day so far this year.
The provisional 2024 total for small boat arrivals is 12,313, up 18% from 10,472 for the same period last year.
It is also 5% higher than the 2022 total of 11,690 at this point.
Fifteen boats were sighted on Tuesday, likely carrying an average of about 59 people per boat.
The fact that 15 boats crossed the border in one day has only happened twice in the past year; the last time was in September of last year.
Arrivals for all of 2023 were 29,437, down 36% from the record high of 45,774 in 2022.
The Government has promised to “stop small boats” but made it clear this does not mean there will be no crossings at all.
Chancellor Rishi Sunak has not defined how low the target figure should be.