Twilight By: Stephenie Meyer

In the story Twilight, Bella Swan moves from Phoenix, Arizona, to Forks, Washington. Forks is a small town that has an overall cool climate and dreary weather.  It is often very rainy and rarely has a sunny day. It is hard for Bella to adjust to the small town of Forks because of its weather.  Her former town, Phoenix, was bright, sunny, and hot everyday.  Forks is the complete opposite of that.  Bella hates the weather but learns to adjust throughout the novel.   
There is no specific year the book Twilight takes place in, but judging from what I have read so far, the story takes place in present tense.
I believe that the setting plays a major role in this story.  Therefore, if the setting changed, the book wouldn't work.  The Cullen's are vampires, therefore they have to live in a dark and dreary environment.  They can't go out in sunlight without being exposed for what they really are.  Forks is a perfect place for the Cullen's because of its weather.  There are rarely sunny days so they are safe from the sunlight.  Clouds, rain, and lack of sun is the best environment for them.
I'm only up to page 146 in Twilight as of right now, so the most important setting is at Forks High School.  A lot has happened and taken place at the high school so far.  Bella meets her friends at the school, and most importantly she meets Edward Cullen and his family at Forks High School.  There are also many important discussions and scenes that take place there. 
"In the Olympic Peninsula of northwest Washington State, a small town names Forks exists under a near-constant cover of clouds. It rains on this inconsequential town more than any other place in the United States of America." pg.3
I believe this quote firmly states the location and the weather of the small town of Forks.  It describes where the towns is, and what the weather is like.