jbunill recommended santa cruz.
I typed out a long post last night about santa cruz and then i hit the wrong key, lost the post and was too tired to do it all again.
But yeah, santa cruz.
Consider the entire county.
From (roughly) may through the end of october the weather is beautiful.
Fog rolls in and out but, for example, i'm about 5 miles in from the coast and the fog may or may be around in the morning when i wake up but it burns off usually by mid morning and always by noon at the latest and then may or may not come back in this far in the evening.
If you're right on the coast you'll be dealing with much more fog but it's lovely and good for your hair and skin

.
And even right on the coast, it rolls in and out (it' not predictable) and there are days, even in the summer, when you won't have any fog.
There are many areas in the county where there is no fog.
Temps in the summer are generally between the mid 70's and mid 80's.
Rain comes in november and winters are wet but there are many beautiful days between the rainy stretches and i've walked on the beach in just a t-shirt in february although that's exceptional.
But we don't get walloped with water as many points to the north.
San Francisco is less than 2 hours to the north, San Jose is just over the hill (bad traffic at rush hour) and Monterey, another town you might consider, is less than an hour to the south.
Santa Cruz is tolerant, liberal, open, friendly and diverse.
There are a variety of ways to live here .... real rural, semi rural, sub-urban (many lovely neighborhoods throughout the county) and urban ... not like nyc obviously but enough of a city vibe in Santa Cruz proper if you need or want it.
There are many living situations in the midst of the redwoods which may seem romantic until you experience an entire winter without sun.
So, though the redwoods are beautiful, as someone who experiences s.a.d., i would not recommend a housing situation like that.
Again, when you think Santa Cruz, think of the entire county ... not just S.C. proper.
It's a very integrated county and each town easily flows into the other and there's a great bus system that serves the whole county.
UCSC is here.
A good enough music and night scene.
Lot's of single guys (or girls if that suits you) in 20's and 30's.
Beautiful and powerful nature and good beaches.
It is expensive here although, needless to say, home prices have gone down but it still isn't cheap.
Finding a good home for less than 6K might be a challenge although i'm a renter so i'm not that tuned into the housing market but i think that a few years ago the average home prices was 7-8K.
So, yeah, consider Santa Cruz or Monterey to the south and MtnSurfer can let you know all about that area.