The novel, Speak by Laurie Halse Anderson, is set in Syracuse, New York. This city is the hometown of the author. Syracuse is located to the South-West of Lake Ontario and less than 150 miles from the Canadian border.
While the novel does not give descriptions of the climate, over the course of the text, one can assume that the winters are very cold and blistery (given being so close to Canada and located in the Upper North of America).
Merryweather High School is a fictional school created for the novel.
While the text does not offer a specific time period to the novel, useful for readers' engagement (given the novel is not dated), the mentioning of the specific cliques (by name) tends to date the novel's setting as being in the 1990s.