For those of you familiar with cycling in Boston and NYC, how hilly is Boston, MA compared to NYC, NY? I'm only familiar with NYC since I live here but will be visiting Boston in a month. I'm riding my single speed (otherwise I wouldn't be asking if I had gears).

I ride 70GI in NYC and can easily climb the bridges, Harlem hill, etc on that ratio. I know the city is considered to be flat but how does it compare to Boston?

I've stayed in Boston a few times & I've been to various places in NY. I'd be confident to say that if you can ride NY, you wouldn't be challenged with Boston's terrain.
Although, you might be let down from the lack of bums when you get to Boston.

stay away from the Beacon Hill area I guess

btw just a heads up, 1st time I drove to Boston (1984) I drove by it & thought, no, was that it? seriously?

Hills aren't really a major issue in the Boston area. Intersections that look like they were designed by someone on shrooms are the bigger problem. I haven't ridden in NYC, but Boston itself is pretty flat. The hills get bigger as the suburbs grow more distant, especially to the west and northwest..

Thanks everybody for your input. Sounds like I'll be ok then as far as gearing. I can always bring a second cog just in case. I'm now super curious to see these intersections . . .

Livedarklions is right. When you see what they call "Squares" you'll wonder if the early colonists ever took Geometry.