Somerville, MA fits the bill pretty well, for sufficiently small values of "decent climate".
Boston is interesting in that population density declines pretty sharply as you move away from the city center. So Boston itself has a population of 600k and skyscrapers, Cambridge has 100k and still feels fairly urban, Arlington and Lexington each have about 40k people and feel like large towns, Bedford and Concord have 15k apiece and feel like small towns, and Carlisle has 4k and feels positively rural. I'm on an acre of land in Bedford, with woods in the back, and only 13 miles outside of Boston.
The northwest suburbs also don't lack cultural activities the way many suburbs do. You've got all the historical sites in Lexington, Bedford, and Concord; the Lexington symphony orchestra; community activities; libraries in each town; band concerts; fireworks displays on July 4; etc. I was going to say "Flipside is that you need a car to get to them," but even that's not really true: a bike path connects the town centers of Bedford, Lexington, Arlington, and the Alewife subway station in Cambridge.
Only problem is that property values are sky-high here, though they seem to be going down fast. The house across the street went on the market for a million, but finally sold for $630k six months later. Houses are still going for $1M+ in Concord and Carlisle.
Well, that and the "sufficiently small values of 'decent climate'". The cold & snow isn't as oppressive in more rural settings though; it's quite pretty out now.