US-Mexico tops busiest flight corridors for December

Other prominent country pairs include Japan to South Korea (2.57 million), India to UAE (2.2 million), Germany to Spain (2.09 million), China to Japan (1.99 million), UK to US (1.87 million), Italy to Spain (1.84 million), and China to Thailand (1.6 million). The UK-US connection is notable for being an intercontinental route within the top ten list.

Cirium data indicates that there are 813 weekly flights across the Atlantic from the UK to the US, with British Airways and Virgin Atlantic leading at 288 and 136 weekly itineraries respectively.

Singapore Airlines operates a fifth-freedom flight across the Atlantic from Singapore to Houston via Manchester but plans to end this service in April 2025.

Beyond these top ten routes, Taiwan-Japan sees 1.5 million seats scheduled for December travel, followed closely by China-South Korea at 1.49 million seats.

The only non-Asian or non-European route among these rankings is Puerto Rico-US—despite being domestic—followed by Germany-Turkey (1.39 million) and Germany-UK (1.34 million). Other significant connections include Saudi Arabia-UAE (1.31 million) and Egypt-Saudi Arabia (1.28 million). European routes such as France-Spain (1.27 million) and Italy-UK (1.23 million) also feature prominently on this list.