The latest provisional Government data shows that some 872 migrants made crossings, an average of 58 per boat, taking the total for the year to 20,973.
The previous high for 2023 was when 756 people made the crossing on August 10.
It comes after the average number of migrants crossing the Channel per boat hit a new monthly high in August, when some 5,369 people made the journey in 102 boats, an average of around 53 migrants per vessel.
This was the highest monthly average since records began in 2018, according to analysis of provisional Government data.
