"Five Things You Need to Know Today" is a Patch column that provides readers with essential, daily information at a glance.
1. It looks like it could be a rainy day for the returning students, as the National Weather Service is predicting a 90-percent chance of rain today into tonight.
2. Today is the first day of school for Concord Public Schools and the Concord-Carlisle Regional School District. Click here for information on bus routes, lunch menus and district calendars. You can also e-mail your first day of school pictures to Chris.Tanguay@Patch.com for this afternoon's slideshow.
3. The Lexington Pops Chorus is holding an open rehearsal tonight at 7:30 p.m. Rehearsals will be held at Hancock United Church of Christ on Massachusetts Avenue in Lexington.
4. There's a book discussion today at 9:30 a.m. at the Concord Free Public Library, Main branch. Author Julia Glass will be discussing "The Widower's Tale."
5. Plenty of students have been moving in and out of Concord over the last couple of weeks for school, but today is the anniversary of another big moving day in Concord. On Sept. 6, 1847, Henry David Thoreau left his cabin on Walden Pond after two years and moved in with Ralph Waldo Emerson and his family.