If timing is everything, then the month you choose to travel to certain European cities can make a significant difference.

Heading to Copenhagen or Scotland? June is ideal for longer daylight and mild temperatures.

For Vienna, aim for March-May or September to catch the start of opera season.

For Budapest or Madrid, the sweet spot is again March-May. And as for Paris? The song is right — April in Paris offers mild temperatures, fewer crowds, and plenty of space at outdoor cafés.