This dark denim trench from Tulle seems to be just the right thing. Forget boxy jean jackets, last season's blazers and easy-to-stain white trenches, this coat would be ideal in San Francisco all year round. Especially lovely paired with a bright dress or trousers I'm sure.
Plus, it's on sale for only $42 (xs and s only)!
PS: This coral dress from a What to Wear in June is also on sale.