There is no 'best time' to travel around Europe as most countries offer plenty to do in every season of the year. The most popular time to travel to countries like Greece, Italy, and Croatia is during the summer months (June, July, and August) so you can make the most of each country's respective beaches and warm weather.Countries such as Iceland, Norway, and Sweden are known for their snowy landscapes and northern lights sightings during Winter (December, January, and February).