Burlington has four genuinely distinct seasons and is worth visiting in any of them. Summer (June through August) is the most popular: the lake is warm, the waterfront is busy, the farmers markets are full, and the outdoor music scene is active. This is the time when Burlington feels most like itself — unhurried, green, and slightly smug about the quality of its food.
Autumn (September and October) brings spectacular foliage to the surrounding countryside. The Green Mountains east of the city turn red and gold, and the Adirondacks across the lake follow a week or two later. Late September and early October are the peak foliage weeks and can see higher prices and more visitors, though Burlington itself is never overwhelmed.
Winter is cold and snowy, with temperatures regularly below freezing from December through February. The ski resorts are the main draw — Stowe (about an hour east) and Sugarbush (about 90 minutes) are among the best in the East. Burlington itself keeps going through the winter, with a lively indoor food and bar scene, but it is quieter and windier on the waterfront than in summer.
Spring (April and May) is mud season — the trails are wet, the weather is unpredictable, and the city is at its least photogenic. It is also when you can get the best deals on accommodation.