freddyg3 is a little bit over enthusiastic, I'd say. Though Boston (actually you should consider it Boston/Cambridge; the two cities stare at each other across the Charles River, and both are vibrant) is indeed lively and full of things to do I would not say that it is the equal to San Francisco - for one thing it practically closes down completely at 2AM unlike San Fran.
All the recreational activities you mention abound in New England (plus the ocean). There are state parks with camping even within 10 miles (to the south) and 18 miles (to the north and to the west) of Boston's downtown.
Weather wise it does precipitate in Boston throughout the year, pretty much every 3-5 days but that makes the weather interesting. In most years the longest dry spell is in late September and the first half of October - wonderfully timed for the beautiful fall foliage (which is indeed just as it is in all the calendars). There are usually 12 - 15 days in summer that are in the 90s with horrible humidity, it is not continuous as freddy3g suggests, but it gets worse every mile south and southwest you go (last summer was wonderfully cool, however). If you live right near the coastline many of these hot, humid days get tempered by cool ocean breezes.
Boston/Cambridge is the most walkable of American cities and has an excellent public transit system for an American city, but living 20 miles from the city of course will put you well into suburbia, some of which is without good local bus service. There is an excellent commuter rail system (much better than San Fran's), and the trains (plus Amtrak) go to nearby other interesting cities (Providence RI, and Portland, Maine). Not only the $ 59 monthly pass, but ALL Boston commuter rail passes also include the subway and local busses. (re: Adam and freddyg3's reference to "the T": the T
is the nickname for the transit system).
Aside from Portland, Providence and Manhattan, the fantastic
city of Montreal is also just a few hours' drive. Vermont as well is its own wonderful world. There is much more variety
within a couple of hours drive from Boston than there is from Eugene. The mountains are not as high as the Cascades , of course, but you can reach them in 1 1/2 hours. There is plenty of remaining wilderness in northern New Hampshire and Maine.
Another good thing about New England - like Oregon it is a center of delicious beer made by micro-breweries.
Bostonians are not unfriendly as a general rule.