I've been thinking about setting this week. It's kind of like deciding where to live. Can you handle the weather? Are the schools good? Is it affordable? (Because, alas, the beach house in Carmel is a tad out of my budget at the moment).
Making a decision about setting forces the characters to interact and react to the surroundings. Gretta responds to the seasons on Orcas Island like I do. The winter scares her inside. The violence of the windstorms and the hidden dangers of the snow storms play into plot. The lilacs in the spring are not to missed... All true.
Yet, the place could be the beach in Malibu with a Santa Ana wind whipping the sand up in stinging sprays, or watching the easy flow of the River Arno in Firenze under an overcast sky. Or it could be in another made up realm--a dreamlike place or another planet.
Each place has seasons and moods, safety or fear, happiness or oppression.