The best time to visit is Patriots' Day (third Monday in April), when Lexington re-enacts the Battle of Lexington on the Battle Green at 6 a.m. — as close to the original hour as possible. Thousands gather in the pre-dawn dark, the Minutemen assemble, and the British Regulars march in. It is one of the most atmospheric historical re-enactments in New England.
The town is pleasant year-round for a day trip from Boston, though the museums are typically closed on Mondays in summer and have reduced hours in winter. The Battle Road Trail is walkable or cycleable whenever the weather allows.