May - October
Who wouldn't want to be in a lakeside city during a gorgeous fall or summer? Thanks to Lake Erie's breezes, Buffalo often avoids the stultifying humidity that can smother all the fun of a July and August vacation. The city gets hot, hot, hot, but it rarely crosses the line into unbearable. Buffalo is alive with humanity in summer, especially at night and on weekends as people flock to street fairs, outdoor jazz festivals and impromptu jam sessions in backyard cafes. As the fall months come, you get the added advantage of fall foliage, a glorious few weeks of swirling red and orange leaves.
January - April
At the risk of sounding harsh, there's really no reason to punish yourself with a Buffalo winter. If you must make the trudge, there is still plenty to see and do—but unless you're made of Teflon, you'll stick to indoor sights. Buffalo isn't the snowiest city in New York (that's probably Syracuse or Ithaca), but it ranks among the coldest, thanks again to that Great Lake to the west. Snowstorms build up on the surface of frozen Lake Erie and blast right into the city. Those squalls don't dump too much white stuff, but they're cold, slushy and damned inconvenient.
The holiday season is especially magical in northern climes, and Buffalo doesn't stint on the festive lighting. The air is a little colder and the wind a little sharper, but it's not yet full-on winter and there's plenty to enjoy. Plus, prices tend to drop across the board once the summer crush is gone. This is the time when weekend greenmarkets swell with homemade apple and pumpkin pies, spiced apple cider, thick wedges of home-cured cheese and all the other harvested fruits from upstate New York's many working farms.