Low-cost carrier Norwegian has seen December passenger numbers rise by 27% to more than 1.6 million.
The increased traffic growth this month is equivalent to the airline’s size in the same month four years ago.
The last month of the year was characterised by solid passenger and capacity growth and a higher load factor, the airline said.
But only 73.3% of flights departed on time, blamed on bad weather in northern Europe at the beginning of December.
The total capacity increased by 48% year on year while the load factor was up 1.9 percentage points to 78% percent.
Chief executive Bjørn Kjos said: “I am pleased that despite our strong capacity growth in December, we are capable of filling the aircraft even more than the same month previous year.
“This proves that Norwegian offers a competitive product both in terms of price and quality.”