Sometimes, you can find the bright side to bad news. First, we'll give you the good news: Airfares from the U.S. to Europe are at their lowest in three years, according to Quartz , which has gathered data from flight-search app Hopper . Flights from New York to Berlin, for instance, average $550 as of Sunday, down $100 from just last week. Flights to Barcelona are $540.The bad news is, obviously, that one of the factors making prices drop is fear of terrorism. Recent headlines in Munich , Nice, Istanbul, Brussels, and Paris are making travelers think twice. The U.S. State Department issued a travel alert for all of Europe back in April, set to expire August 31.This is how travel author Rick Steves puts terrorism fears in perspective: "Travelers should understand the risk of terrorism in a cold, logical, statistical way. Your odds of being killed by a terrorist overseas or in the air are 1 in 20 million ( Washington Post and Time ). Your odds of being struck by lightning are 1 in 10 million ( New York Times ). Your odds of being killed by gunfire in the United States are 1 in 32,250 ( New York Times )."There are more mundane reasons for the lower costs, too, including cheap fuel costs and an overestimated demand, Quartz adds. Then, there's the economic fallout the continent is still experiencing after the United Kingdom voted to leave the European Union. Hopper found that flights to the U.K. and Europe went down 10-15% immediately after the Brexit vote. This also means that once you get overseas, the dollar is pretty strong against the Euro, at $1.10 to 1 euro (per Google) at the time of publication.