September through November is peak—fall foliage around 15°C–20°C (60°F–70°F), perfect for walking around without sweating or freezing. Spring (April-May) works too once winter finally quits, though temps bounce around 10°C–18°C (50°F–65°F). Summer (June-August) hits 25°C–30°C (75°F–85°F) with occasional brutal humidity, but that's when the city feels most alive—outdoor concerts, harbor cruises, rooftop bars. Winter (December-March) drops to -5°C to 5°C (20°F–40°F) with snow that sticks around—bring real winter gear. Marathon week in April and college move-in (September) jam hotels solid, so book early.
Logan Airport sits right in the city—you can see downtown from the runway. Direct flights run from most major US cities, plus European routes to London, Paris, Dublin. Budget carriers and legacy airlines both fly here, so shop around. Book six to eight weeks ahead for domestic, longer for international. Flying Tuesday or Wednesday beats weekend prices if you've got flexibility.
US citizens obviously don't need anything. Visa Waiver Program countries get 90 days with ESTA approval. Everyone else needs a standard US tourist visa, depending on their passport.
Quit scrolling through fall foliage pics—book your cheap flight to Boston and hit a city where American history happened, the seafood's legit, and people still argue about the best route to avoid traffic.