Just because you're not heading to Paris or Rome this summer doesn't mean you won't come up against crowds.
New data from Kayak.com's 2016 Summer Travel Hacker Guide found summer flight searches are trending upward for cities that aren't among the usual suspects for that peak-season period. Among the hot spots: Reykjavik (where searches for this summer are up 75 percent compared with last year), Krakow, Poland (up 53 percent) and Dublin (up 30 percent).
"It reveals some fascinating places that are emerging more," said David Solomito, director of brand marketing for Kayak. "It confirms anecdotally what we're hearing, where the trendsetters are headed."
Based on Kayak's price data from user searches, here are the best times to visit newly trending European destinations between Memorial Day and Labor Day this year — and how far ahead you might want to book to snag great deals.
— By CNBC's Kelli B. Grant
Posted 13 April 2016