Transatlantic · May–Jun & Sep
Boston eastward, charted honestly.
Logan is New England's transatlantic anchor. The almanac follows eight European gateways with credible Boston nonstops or one-stops.
The Aer Lingus / JetBlue partnership routinely sets the floor to Dublin. Icelandair's KEF connection is the cheapest way to most of continental Europe in shoulder seasons, especially if you can use a free Reykjavik stopover.
Avoid the late-June through mid-August peak: London, Paris, and Amsterdam fares roughly double versus the May–June window.